diff --git a/Services/UIComponent/AdvancedSelectionList/classes/class.ilAdvancedSelectionListGUI.php b/Services/UIComponent/AdvancedSelectionList/classes/class.ilAdvancedSelectionListGUI.php
index ba5929307bad..53c8ce29e7a5 100755
--- a/Services/UIComponent/AdvancedSelectionList/classes/class.ilAdvancedSelectionListGUI.php
+++ b/Services/UIComponent/AdvancedSelectionList/classes/class.ilAdvancedSelectionListGUI.php
@@ -443,7 +443,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
         $items = $this->getItems();
 
         // do not show list, if no item is in list
-        if (count($items) == 0 && !$this->getAsynch() && $this->getGroupedList() == null) {
+        if (count($items) === 0 && !$this->getAsynch() && $this->getGroupedList() === null) {
             return "";
         }
 
@@ -477,11 +477,11 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
             $tpl->setCurrentBlock("asynch_request");
             $tpl->setVariable("IMG_LOADER", ilUtil::getImagePath("loader.svg"));
             $tpl->parseCurrentBlock();
-        } elseif ($this->getGroupedList() != null) {
+        } elseif ($this->getGroupedList() !== null) {
             $tpl->setVariable("GROUPED_LIST_HTML", $this->getGroupedList()->getHTML());
         } else {
             foreach ($items as $item) {
-                $this->css_row = ($this->css_row != "tblrow1_mo")
+                $this->css_row = ($this->css_row !== "tblrow1_mo")
                     ? "tblrow1_mo"
                     : "tblrow2_mo";
 
@@ -506,16 +506,14 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
                     }
                 }
 
-                if ($this->getOnClickMode() ==
-                    self::ON_ITEM_CLICK_HREF ||
-                    $this->getItemLinkClass() != "") {
+                if ($this->getOnClickMode() === self::ON_ITEM_CLICK_HREF || $this->getItemLinkClass() !== "") {
                     if ($item["frame"]) {
                         $tpl->setCurrentBlock("frame");
                         $tpl->setVariable("TARGET_ITEM", $item["frame"]);
                         $tpl->parseCurrentBlock();
                     }
 
-                    if ($this->getItemLinkClass() != "") {
+                    if ($this->getItemLinkClass() !== "") {
                         $tpl->setCurrentBlock("item_link_class");
                         $tpl->setVariable("ITEM_LINK_CLASS", $this->getItemLinkClass());
                         $tpl->parseCurrentBlock();
@@ -543,8 +541,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
                 }
 
                 $tpl->setCurrentBlock("item");
-                if ($this->getOnClickMode() ==
-                    self::ON_ITEM_CLICK_HREF) {
+                if ($this->getOnClickMode() === self::ON_ITEM_CLICK_HREF) {
                     if ($item["prevent_background_click"]) {
                         $tpl->setVariable("ONCLICK_ITEM", '');
                     } elseif ($item["onclick"] == "" && $item["frame"] != "") {       // see #28730
@@ -558,24 +555,21 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
                             'onclick="' . "return " . $item["onclick"] . ";" . '"'
                         );
                     }
-                } elseif ($this->getOnClickMode() ==
-                    self::ON_ITEM_CLICK_FORM_SUBMIT) {
+                } elseif ($this->getOnClickMode() === self::ON_ITEM_CLICK_FORM_SUBMIT) {
                     $tpl->setVariable(
                         "ONCLICK_ITEM",
                         'onclick="return il.AdvancedSelectionList.submitForm(\'' . $this->getId() . '\'' .
                             ", '" . $this->form_mode["select_name"] . "','" . $item["value"] . "'," .
                             "'" . $this->on_click_form_id . "','" . $this->form_mode["button_cmd"] . "');\""
                     );
-                } elseif ($this->getOnClickMode() ==
-                    self::ON_ITEM_CLICK_FORM_SELECT) {
+                } elseif ($this->getOnClickMode() === self::ON_ITEM_CLICK_FORM_SELECT) {
                     $tpl->setVariable(
                         "ONCLICK_ITEM",
                         'onclick="return il.AdvancedSelectionList.selectForm(\'' . $this->getId() . '\'' .
                             ", '" . $this->form_mode["select_name"] . "','" . $item["value"] . "'," .
                             "'" . $item["title"] . "');\""
                     );
-                } elseif ($this->getOnClickMode() ==
-                    self::ON_ITEM_CLICK_NOP) {
+                } elseif ($this->getOnClickMode() === self::ON_ITEM_CLICK_NOP) {
                     $tpl->setVariable(
                         "ONCLICK_ITEM",
                         'onclick="il.AdvancedSelectionList.clickNop(\'' . $this->getId() . '\'' .
@@ -619,7 +613,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
             }
 
             // output hidden input, if click mode is form submission
-            if ($this->getOnClickMode() == self::ON_ITEM_CLICK_FORM_SUBMIT) {
+            if ($this->getOnClickMode() === self::ON_ITEM_CLICK_FORM_SUBMIT) {
                 $tpl->setCurrentBlock("hidden_input");
                 $tpl->setVariable("HID", $this->getId());
                 $tpl->parseCurrentBlock();
@@ -630,7 +624,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
             }
 
             // output hidden input and initialize
-            if ($this->getOnClickMode() == self::ON_ITEM_CLICK_FORM_SELECT) {
+            if ($this->getOnClickMode() === self::ON_ITEM_CLICK_FORM_SELECT) {
                 $tpl->setCurrentBlock("hidden_input");
                 $tpl->setVariable("HID", $this->getId());
                 $tpl->parseCurrentBlock();
@@ -649,7 +643,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
             return $tpl->get("cmd_table");
         }
 
-        if ($this->getGroupedList() == null) {
+        if ($this->getGroupedList() === null) {
             $tpl->setCurrentBlock("dd_content");
             if ($this->getPullRight()) {
                 $tpl->setVariable("UL_CLASS", "dropdown-menu pull-right");
@@ -660,7 +654,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
             $tpl->parseCurrentBlock();
         }
 
-        if ($this->getHeaderIcon() != self::NO_ICON) {
+        if ($this->getHeaderIcon() !== self::NO_ICON) {
             $tpl->setCurrentBlock("top_img");
             switch ($this->getHeaderIcon()) {
                 case self::ICON_CONFIG:
@@ -690,7 +684,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
         $cfg["trigger_event"] = $this->getTriggerEvent();
         $cfg["auto_hide"] = $this->getAutoHide();
 
-        if ($this->getSelectCallback() != "") {
+        if ($this->getSelectCallback() !== "") {
             $cfg["select_callback"] = $this->getSelectCallback();
         }
         $cfg["anchor_id"] = "ilAdvSelListAnchorElement_" . $this->getId();
@@ -707,8 +701,8 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
         //echo htmlentities(ilJsonUtil::encode($cfg));
         
         $tpl->setVariable("TXT_SEL_TOP", $this->getListTitle());
-        if ($this->getListTitle() == "" || $this->getAriaListTitle() != "") {
-            $aria_title = ($this->getAriaListTitle() != "")
+        if ($this->getListTitle() === "" || $this->getAriaListTitle() !== "") {
+            $aria_title = ($this->getAriaListTitle() !== "")
                 ? $this->getAriaListTitle()
                 : $this->lng->txt("actions");
             $tpl->setVariable("TXT_ARIA_TOP", $aria_title);
@@ -741,7 +735,7 @@ public function getHTML(bool $a_only_cmd_list_asynch = false) : string
         }
 
 
-        if ($this->getSelectionHeaderSpanClass() != "") {
+        if ($this->getSelectionHeaderSpanClass() !== "") {
             $tpl->setVariable(
                 "CLASS_SEL_TOP_SPAN",
                 $this->getSelectionHeaderSpanClass()
diff --git a/Services/UIComponent/CharSelector/classes/class.ilCharSelectorGUI.php b/Services/UIComponent/CharSelector/classes/class.ilCharSelectorGUI.php
index 38052cdb6231..d3d0a18ab184 100755
--- a/Services/UIComponent/CharSelector/classes/class.ilCharSelectorGUI.php
+++ b/Services/UIComponent/CharSelector/classes/class.ilCharSelectorGUI.php
@@ -77,7 +77,7 @@ public static function _isAllowed() : bool
         // with correct case for checking parent classes
         $class = false;
         foreach ($ilCtrl->getCallHistory() as $call) {
-            if ($call['mode'] == 'execComm') {
+            if ($call['mode'] === 'execComm') {
                 $class = $call['class'];
             }
         }
diff --git a/Services/UIComponent/CharSelector/classes/class.ilCharSelectorRadioGroupInputGUI.php b/Services/UIComponent/CharSelector/classes/class.ilCharSelectorRadioGroupInputGUI.php
index 12e09054a5bb..9d18445f1396 100644
--- a/Services/UIComponent/CharSelector/classes/class.ilCharSelectorRadioGroupInputGUI.php
+++ b/Services/UIComponent/CharSelector/classes/class.ilCharSelectorRadioGroupInputGUI.php
@@ -35,9 +35,9 @@ public function checkInput() : bool
             return false;
         }
 
-        if ($this->int('char_selector_availability') == ilCharSelectorConfig::ENABLED
-            and trim(implode("", $this->strArray('char_selector_blocks'))) == ""
-            and trim($this->str('char_selector_custom_items')) == '') {
+        if ($this->int('char_selector_availability') === ilCharSelectorConfig::ENABLED
+            && trim(implode("", $this->strArray('char_selector_blocks'))) === ""
+            && trim($this->str('char_selector_custom_items')) === '') {
             $this->setAlert($lng->txt("char_selector_msg_blocks_or_custom_needed"));
             return false;
         } else {
diff --git a/Services/UIComponent/CharSelector/classes/ilCharSelectorConfig.php b/Services/UIComponent/CharSelector/classes/ilCharSelectorConfig.php
index db55b479d0a5..78a9b41ccf1f 100644
--- a/Services/UIComponent/CharSelector/classes/ilCharSelectorConfig.php
+++ b/Services/UIComponent/CharSelector/classes/ilCharSelectorConfig.php
@@ -302,7 +302,7 @@ public static function _getCurrentConfig(ilObjTest $a_test_obj = null) : self
         $admin_config = new self(self::CONTEXT_ADMIN);
         $admin_config->setAvailability($ilSetting->get('char_selector_availability'));
         $admin_config->setDefinition($ilSetting->get('char_selector_definition'));
-        if ($admin_config->getAvailability() == self::INACTIVE) {
+        if ($admin_config->getAvailability() === self::INACTIVE) {
             // a globally inactive selector can't be overwritten by users or tests
             return $admin_config;
         }
@@ -312,7 +312,7 @@ public static function _getCurrentConfig(ilObjTest $a_test_obj = null) : self
             $test_config = new self(self::CONTEXT_TEST);
             $test_config->setAvailability($a_test_obj->getCharSelectorAvailability());
             $test_config->setDefinition($a_test_obj->getCharSelectorDefinition());
-            if ($test_config->getAvailability() != self::INHERIT) {
+            if ($test_config->getAvailability() !== self::INHERIT) {
                 // a specific test configuration has precedence over user configuration
                 return $test_config;
             }
@@ -322,7 +322,7 @@ public static function _getCurrentConfig(ilObjTest $a_test_obj = null) : self
         $user_config = new self(self::CONTEXT_USER);
         $user_config->setAvailability($ilUser->getPref('char_selector_availability'));
         $user_config->setDefinition($ilUser->getPref('char_selector_definition'));
-        if ($user_config->getAvailability() != self::INHERIT) {
+        if ($user_config->getAvailability() !== self::INHERIT) {
             // take user specific config
             return $user_config;
         } else {
@@ -419,16 +419,16 @@ public function setDefinition(string $a_definition = '') : void
         $this->custom_items = array();
 
         // set the default definition to all unicode blocks
-        if (trim($a_definition) == '') {
+        if (trim($a_definition) === '') {
             $a_definition = "[all]";
         }
         
         // analyze definition items
         $items = explode(' ', $a_definition);
         foreach ($items as $item) {
-            if (strlen($block_name = $this->extractUnicodeBlock($item))) {
+            if (($block_name = $this->extractUnicodeBlock($item)) !== '') {
                 $this->added_blocks[] = $block_name;
-            } elseif ($item != '') {
+            } elseif ($item !== '') {
                 $this->custom_items[] = trim($item);
             }
         }
@@ -475,7 +475,7 @@ public function getBlockTitle(string $a_block_name) : string
         global $lng;
         
         $langvar = 'char_selector_unicode_' . $a_block_name;
-        if ($lng->txt($langvar) != '-' . $langvar . '-') {
+        if ($lng->txt($langvar) !== '-' . $langvar . '-') {
             return $lng->txt($langvar);
         } else {
             return self::$unicode_blocks[$a_block_name][0];
diff --git a/Services/UIComponent/Explorer/classes/class.ilExplorer.php b/Services/UIComponent/Explorer/classes/class.ilExplorer.php
index c18d0f8295cc..ffc8fb76e6f5 100755
--- a/Services/UIComponent/Explorer/classes/class.ilExplorer.php
+++ b/Services/UIComponent/Explorer/classes/class.ilExplorer.php
@@ -196,7 +196,7 @@ public function setOrderColumn(string $a_column) : void
 
     public function setOrderDirection(string $a_direction) : void
     {
-        if ($a_direction == "desc") {
+        if ($a_direction === "desc") {
             $this->order_direction = $a_direction;
         } else {
             $this->order_direction = "asc";
@@ -318,11 +318,7 @@ public function isClickable(
         // only the type determines, wether an object should be clickable or not
         // but this method can be overwritten and make $exp->setFilterMode(IL_FM_NEGATIVE);use of the ref id
         // (this happens e.g. in class ilRepositoryExplorerGUI)
-        if ($this->is_clickable[$a_type] == "n") {
-            return false;
-        } else {
-            return true;
-        }
+        return $this->is_clickable[$a_type] !== "n";
     }
 
     public function setPostSort(bool $a_sort) : void
@@ -408,7 +404,7 @@ public function setOutput(
                 }
                 //echo "<br>-".$object["child"]."-".$this->forceExpanded($object["child"])."-";
                 //ask for FILTER
-                if ($this->filtered == false or $this->checkFilter($object["type"]) == false) {
+                if ($this->filtered === false || $this->checkFilter($object["type"]) === false) {
                     if ($this->isVisible($object['child'], $object['type'])) {
                         #echo 'CHILD getIndex() '.$object['child'].' parent: '.$this->getRoot();
                         if ($object["child"] != $this->getRoot()) {
@@ -431,7 +427,7 @@ public function setOutput(
                         }
 
                         // fix explorer (sometimes explorer disappears)
-                        if ($parent_index == 0) {
+                        if ($parent_index === 0) {
                             if (!$this->expand_all && !in_array($object["parent"], $this->expanded)) {
                                 $this->expanded[] = $object["parent"];
                             }
@@ -541,9 +537,9 @@ public function getOutput() : string
         $tpl_tree = new ilTemplate("tpl.tree.html", true, true, "Services/UIComponent/Explorer");
         
         // updater
-        if (($this->requestStr("ict") != "" ||
-            $this->requestStr("collapseAll") != "" ||
-            $this->requestStr("expandAll") != "") && $this->up_frame != "") {
+        if (($this->requestStr("ict") !== "" ||
+            $this->requestStr("collapseAll") !== "" ||
+            $this->requestStr("expandAll") !== "") && $this->up_frame !== "") {
             $tpl_tree->setCurrentBlock("updater");
             $tpl_tree->setVariable("UPDATE_FRAME", $this->up_frame);
             $tpl_tree->setVariable("UPDATE_SCRIPT", $this->up_script);
@@ -584,12 +580,12 @@ public function getOutput() : string
         $this->handleListEndTags($tpl_tree, $cur_depth, -1);
         
         $tpl_tree->setVariable("TREE_LEAD", "");
-        if ($this->tree_lead != "") {
+        if ($this->tree_lead !== "") {
             $tpl_tree->setCurrentBlock("tree_lead");
             $tpl_tree->setVariable("TREE_LEAD", $this->tree_lead);
             $tpl_tree->parseCurrentBlock();
         }
-        if ($this->getId() != "") {
+        if ($this->getId() !== "") {
             $tpl_tree->setVariable("TREE_ID", 'id="' . $this->getId() . '_tree"');
         }
 
@@ -600,10 +596,10 @@ public function getOutput() : string
             $mtpl->setVariable("LOCATION_STYLESHEET", ilUtil::getStyleSheetLocation());
             $mtpl->setVariable("BODY_CLASS", "il_Explorer");
             $mtpl->addBlockFile("CONTENT", "content", "tpl.explorer.html");
-            if ($this->getTitle() != "") {
+            if ($this->getTitle() !== "") {
                 $mtpl->setVariable("TXT_EXPLORER_HEADER", $this->getTitle());
             }
-            if ($this->getId() != "") {
+            if ($this->getId() !== "") {
                 $mtpl->setVariable("ID", 'id="' . $this->getId() . '"');
             }
             $mtpl->setVariable("IMG_SPACE", ilUtil::getImagePath("spacer.png", false));
@@ -688,7 +684,7 @@ public function formatObject(
 
         $pic = false;
         foreach ((array) $a_option["tab"] as $picture) {
-            if ($picture == 'plus') {
+            if ($picture === 'plus') {
                 $tpl->setCurrentBlock("expander");
                 $tpl->setVariable("EXP_DESC", $lng->txt("collapsed"));
                 $tpl->setVariable("LINK_NAME", $a_node_id);
@@ -705,7 +701,7 @@ public function formatObject(
                 $pic = true;
             }
 
-            if ($picture == 'forceexp') {
+            if ($picture === 'forceexp') {
                 $tpl->setCurrentBlock("expander");
                 $tpl->setVariable("EXP_DESC", $lng->txt("expanded"));
                 $target = $this->createTarget('+', $a_node_id);
@@ -716,7 +712,7 @@ public function formatObject(
                 $pic = true;
             }
 
-            if ($picture == 'minus' && $this->show_minus) {
+            if ($picture === 'minus' && $this->show_minus) {
                 $tpl->setCurrentBlock("expander");
                 $tpl->setVariable("EXP_DESC", $lng->txt("expanded"));
                 $tpl->setVariable("LINK_NAME", $a_node_id);
@@ -753,7 +749,7 @@ public function formatObject(
             $tpl->parseCurrentBlock();
         }
         
-        if (strlen($sel = $this->buildSelect($a_node_id, $a_option['type']))) {
+        if (($sel = $this->buildSelect($a_node_id, $a_option['type'])) !== '') {
             $tpl->setCurrentBlock('select');
             $tpl->setVariable('OBJ_SEL', $sel);
             $tpl->parseCurrentBlock();
@@ -768,7 +764,7 @@ public function formatObject(
                 
             $style_class = $this->getNodeStyleClass($a_node_id, $a_option["type"]);
             
-            if ($style_class != "") {
+            if ($style_class !== "") {
                 $tpl->setVariable("A_CLASS", ' class="' . $style_class . '" ');
             }
 
@@ -794,7 +790,7 @@ public function formatObject(
                 )
             );
             $frame_target = $this->buildFrameTarget($a_option["type"], $a_node_id, $a_option["obj_id"]);
-            if ($frame_target != "") {
+            if ($frame_target !== "") {
                 $tpl->setVariable("TARGET", " target=\"" . $frame_target . "\"");
             }
         } else {			// output text only
@@ -916,14 +912,14 @@ public function createTarget(
         // SET expand parameter:
         //     positive if object is expanded
         //     negative if object is compressed
-        $a_node_id = $a_type == '+' ? $a_node_id : -(int) $a_node_id;
+        $a_node_id = $a_type === '+' ? $a_node_id : -(int) $a_node_id;
 
         $sep = (is_int(strpos($this->expand_target, "?")))
             ? "&"
             : "?";
         
         // in current tree flag
-        $ict_str = ($a_highlighted_subtree || $this->highlighted == "")
+        $ict_str = ($a_highlighted_subtree || $this->highlighted === "")
             ? "&ict=1"
             : "";
         if ($this->getAsynchExpanding()) {
@@ -1003,7 +999,7 @@ public function addFilter(string $a_item) : bool
         if (is_array($this->filter)) {
             //run through filter
             foreach ($this->filter as $item) {
-                if ($item == $a_item) {
+                if ($item === $a_item) {
                     return false;
                 }
             }
@@ -1024,7 +1020,7 @@ public function delFilter(string $a_item) : bool
             $tmp = array();
 
             foreach ($this->filter as $item) {
-                if ($item != $a_item) {
+                if ($item !== $a_item) {
                     $tmp[] = $item;
                 } else {
                     $deleted = 1;
@@ -1036,11 +1032,7 @@ public function delFilter(string $a_item) : bool
             return false;
         }
 
-        if ($deleted == 1) {
-            return true;
-        } else {
-            return false;
-        }
+        return $deleted === 1;
     }
 
     /**
@@ -1099,7 +1091,7 @@ public function checkFilter(string $a_item) : bool
             $ret = false;
         }
 
-        if ($this->getFilterMode() == IL_FM_NEGATIVE) {
+        if ($this->getFilterMode() === IL_FM_NEGATIVE) {
             return $ret;
         } else {
             return !$ret;
@@ -1113,7 +1105,7 @@ public function sortNodes(array $a_nodes, $a_parent_obj_id) : array
     {
         $adm_node = null;
         foreach ($a_nodes as $key => $node) {
-            if ($node["type"] == "adm") {
+            if ($node["type"] === "adm") {
                 $match = $key;
                 $adm_node = $node;
                 break;
diff --git a/Services/UIComponent/Explorer2/classes/class.ilExplorerBaseGUI.php b/Services/UIComponent/Explorer2/classes/class.ilExplorerBaseGUI.php
index 4cdeb64da21d..1d8521982ac5 100644
--- a/Services/UIComponent/Explorer2/classes/class.ilExplorerBaseGUI.php
+++ b/Services/UIComponent/Explorer2/classes/class.ilExplorerBaseGUI.php
@@ -252,7 +252,7 @@ public function getNodeTarget($a_node) : string
      */
     public function getNodeOnClick($a_node) : string
     {
-        if ($this->select_postvar != "") {
+        if ($this->select_postvar !== "") {
             return $this->getSelectOnClick($a_node);
         }
         return "";
@@ -421,8 +421,8 @@ public function getOfflineMode() : bool
      */
     public function handleCommand() : bool
     {
-        if ($this->requested_exp_cmd != "" &&
-            $this->requested_exp_cont == $this->getContainerId()) {
+        if ($this->requested_exp_cmd !== "" &&
+            $this->requested_exp_cont === $this->getContainerId()) {
             $cmd = $this->requested_exp_cmd;
             if (in_array($cmd, array("openNode", "closeNode", "getNodeAsync"))) {
                 $this->$cmd();
@@ -479,7 +479,7 @@ public function getNodeAsync() : string
             $this->open_nodes[] = $root;
         }
 
-        if ($this->requested_node_id != "") {
+        if ($this->requested_node_id !== "") {
             $id = $this->getNodeIdForDomNodeId($this->requested_node_id);
             $this->setSearchTerm(ilUtil::stripSlashes($this->requested_searchterm));
             $this->renderChilds($id, $etpl);
@@ -568,7 +568,11 @@ public function getOnLoadCode() : string
             "html_data" => array()
         );
 
-        return 'il.Explorer2.init(' . json_encode($config) . ', ' . json_encode($js_tree_config) . ');';
+        return (
+            'il.Explorer2.init(' .
+            json_encode($config, JSON_THROW_ON_ERROR) . ', ' .
+            json_encode($js_tree_config, JSON_THROW_ON_ERROR) . ');'
+        );
     }
 
     protected function getJSTreePlugins() : array
@@ -586,11 +590,7 @@ public static function init(ilGlobalTemplateInterface $a_main_tpl = null) : void
     {
         global $DIC;
 
-        if ($a_main_tpl == null) {
-            $tpl = $DIC["tpl"];
-        } else {
-            $tpl = $a_main_tpl;
-        }
+        $tpl = $a_main_tpl ?? $DIC["tpl"];
 
         iljQueryUtil::initjQuery($tpl);
 
@@ -675,7 +675,7 @@ public function renderNode($a_node, ilTemplate $tpl) : void
             $this->listItemStart($tpl, $a_node);
 
             // select mode?
-            if ($this->select_postvar != "" && $this->isNodeSelectable($a_node)) {
+            if ($this->select_postvar !== "" && $this->isNodeSelectable($a_node)) {
                 if ($this->select_multi) {
                     $tpl->setCurrentBlock("cb");
                     if (in_array($this->getNodeId($a_node), $this->selected_nodes)) {
@@ -699,7 +699,7 @@ public function renderNode($a_node, ilTemplate $tpl) : void
                 $tpl->touchBlock("hl");
             }
             $tpl->setCurrentBlock("content");
-            if ($this->getNodeIcon($a_node) != "") {
+            if ($this->getNodeIcon($a_node) !== "") {
                 $tpl->setVariable("ICON", ilUtil::img($this->getNodeIcon($a_node), $this->getNodeIconAlt($a_node)) . " ");
             }
             $tpl->setVariable("CONTENT", $this->getNodeContent($a_node));
@@ -707,7 +707,7 @@ public function renderNode($a_node, ilTemplate $tpl) : void
                 $tpl->setVariable("HREF", $this->getNodeHref($a_node));
             }
             $target = $this->getNodeTarget($a_node);
-            if ($target != "") {
+            if ($target !== "") {
                 $targetRelatedParams = array(
                     'target="' . $target . '"'
                 );
@@ -723,7 +723,7 @@ public function renderNode($a_node, ilTemplate $tpl) : void
                 $tpl->setVariable("A_CLASS", 'class="disabled"');
             } else {
                 $onclick = $this->getNodeOnClick($a_node);
-                if ($onclick != "") {
+                if ($onclick !== "") {
                     $tpl->setVariable("ONCLICK", 'onclick="' . $onclick . '"');
                 }
             }
@@ -751,7 +751,7 @@ final public function renderChilds($a_node_id, ilTemplate $tpl) : void
         $childs = $this->getChildsOfNode($a_node_id);
         $childs = $this->sortChilds($childs, $a_node_id);
 
-        if (count($childs) > 0 || ($this->getSearchTerm() != "" && $this->requested_node_id == $this->getDomNodeIdForNodeId($a_node_id))) {
+        if (count($childs) > 0 || ($this->getSearchTerm() !== "" && $this->requested_node_id === $this->getDomNodeIdForNodeId($a_node_id))) {
             // collect visible childs
 
             $visible_childs = [];
@@ -770,15 +770,14 @@ final public function renderChilds($a_node_id, ilTemplate $tpl) : void
 
             // search field, if too many childs
             $any = false;
-            if ($this->getChildLimit() > 0 && $this->getChildLimit() < $cnt_child
-                || ($this->getSearchTerm() != "")) {
+            if (($this->getChildLimit() > 0 && $this->getChildLimit() < $cnt_child) || $this->getSearchTerm() !== "") {
                 if (!$any) {
                     $this->listStart($tpl);
                     $any = true;
                 }
                 $tpl->setCurrentBlock("list_search");
                 $tpl->setVariable("SEARCH_CONTAINER_ID", $a_node_id);
-                if ($this->requested_node_id == $this->getDomNodeIdForNodeId($a_node_id)) {
+                if ($this->requested_node_id === $this->getDomNodeIdForNodeId($a_node_id)) {
                     $tpl->setVariable("SEARCH_VAL", $this->getSearchTerm());
                 }
                 $tpl->parseCurrentBlock();
diff --git a/Services/UIComponent/Explorer2/classes/class.ilExplorerSelectInputGUI.php b/Services/UIComponent/Explorer2/classes/class.ilExplorerSelectInputGUI.php
index 9c89480e12fe..80432566b651 100644
--- a/Services/UIComponent/Explorer2/classes/class.ilExplorerSelectInputGUI.php
+++ b/Services/UIComponent/Explorer2/classes/class.ilExplorerSelectInputGUI.php
@@ -118,8 +118,8 @@ public function checkInput() : bool
         
         // check required
         if ($this->getRequired()) {
-            if ((!$this->multi_nodes && trim($this->getInput()) == "") ||
-                ($this->multi_nodes && count($this->getInput()) == 0)) {
+            if ((!$this->multi_nodes && trim($this->getInput()) === "") ||
+                ($this->multi_nodes && count($this->getInput()) === 0)) {
                 $this->setAlert($lng->txt("msg_input_is_required"));
                 return false;
             }
@@ -151,7 +151,7 @@ public function render(string $a_mode = "property_form") : string
 
         $tpl = new ilTemplate("tpl.prop_expl_select.html", true, true, "Services/UIComponent/Explorer2");
 
-        if ($a_mode != "property_form") {
+        if ($a_mode !== "property_form") {
             $tpl->touchBlock("tiny_presentation");
         }
 
diff --git a/Services/UIComponent/Explorer2/classes/class.ilTreeExplorerGUI.php b/Services/UIComponent/Explorer2/classes/class.ilTreeExplorerGUI.php
index 90d61a0029a4..f23e1c5563eb 100644
--- a/Services/UIComponent/Explorer2/classes/class.ilTreeExplorerGUI.php
+++ b/Services/UIComponent/Explorer2/classes/class.ilTreeExplorerGUI.php
@@ -133,7 +133,7 @@ protected function preloadChilds() : void
             $this->all_childs[$s["child"]] = $s;
         }
 
-        if ($this->order_field != "") {
+        if ($this->order_field !== "") {
             foreach ($this->childs as $k => $childs) {
                 $this->childs[$k] = ilArrayUtil::sortArray(
                     $childs,
@@ -145,7 +145,7 @@ protected function preloadChilds() : void
         }
 
         // sort childs and store prev/next reference
-        if ($this->order_field == "") {
+        if ($this->order_field === "") {
             $this->all_childs =
                 ilArrayUtil::sortArray($this->all_childs, "lft", "asc", true, true);
             $prev = false;
@@ -174,14 +174,14 @@ public function getSuccessorNode(
         $a_node_id,
         string $a_type = ""
     ) {
-        if ($this->order_field != "") {
+        if ($this->order_field !== "") {
             die("ilTreeExplorerGUI::getSuccessorNode not implemented for order field " . $this->order_field);
         }
 
         if ($this->preloaded) {
             $next_id = $a_node_id;
-            while (($next_id = $this->all_childs[$next_id]["next_node_id"]) && $a_type != "" &&
-                $this->all_childs[$next_id]["type"] != $a_type) {
+            while (($next_id = $this->all_childs[$next_id]["next_node_id"]) && $a_type !== "" &&
+                $this->all_childs[$next_id]["type"] !== $a_type) {
                 // do nothing
             }
             if ($next_id) {
@@ -201,7 +201,7 @@ public function getSuccessorNode(
      */
     public function getChildsOfNode($a_parent_node_id) : array
     {
-        if ($this->preloaded && $this->getSearchTerm() == "") {
+        if ($this->preloaded && $this->getSearchTerm() === "") {
             if (isset($this->childs[$a_parent_node_id]) && is_array($this->childs[$a_parent_node_id])) {
                 return $this->childs[$a_parent_node_id];
             }
@@ -209,7 +209,7 @@ public function getChildsOfNode($a_parent_node_id) : array
         }
 
         $wl = $this->getTypeWhiteList();
-        if (is_array($wl) && count($wl) > 0) {
+        if (count($wl) > 0) {
             $childs = $this->tree->getChildsByTypeFilter($a_parent_node_id, $wl, $this->getOrderField());
         } else {
             $childs = $this->tree->getChilds($a_parent_node_id, $this->getOrderField());
@@ -220,7 +220,7 @@ public function getChildsOfNode($a_parent_node_id) : array
         if (is_array($bl) && count($bl) > 0) {
             $bl_childs = array();
             foreach ($childs as $k => $c) {
-                if (!in_array($c["type"], $bl) && ($this->matches($c) || $this->requested_node_id != $this->getDomNodeIdForNodeId($a_parent_node_id))) {
+                if (!in_array($c["type"], $bl, true) && ($this->matches($c) || $this->requested_node_id !== $this->getDomNodeIdForNodeId($a_parent_node_id))) {
                     $bl_childs[$k] = $c;
                 }
             }
@@ -229,7 +229,7 @@ public function getChildsOfNode($a_parent_node_id) : array
 
         $final_childs = [];
         foreach ($childs as $k => $c) {
-            if ($this->matches($c) || $this->requested_node_id != $this->getDomNodeIdForNodeId($a_parent_node_id)) {
+            if ($this->matches($c) || $this->requested_node_id !== $this->getDomNodeIdForNodeId($a_parent_node_id)) {
                 $final_childs[$k] = $c;
             }
         }
@@ -243,11 +243,10 @@ public function getChildsOfNode($a_parent_node_id) : array
      */
     protected function matches($node) : bool
     {
-        if ($this->getSearchTerm() == "" ||
-            is_int(stripos($this->getNodeContent($node), $this->getSearchTerm()))) {
-            return true;
-        }
-        return false;
+        return (
+            $this->getSearchTerm() === "" ||
+            is_int(ilStr::striPos($this->getNodeContent($node), $this->getSearchTerm()))
+        );
     }
 
     
@@ -255,7 +254,7 @@ protected function matches($node) : bool
      * Get id for node
      *
      * @param object|array $a_node
-     * @return string id
+     * @return string
      */
     public function getNodeId($a_node)
     {
@@ -290,15 +289,12 @@ public function getRootNode()
     /**
      * @param int|string $a_root
      */
-    public function setRootId($a_root)
+    public function setRootId($a_root) : void
     {
         $this->root_id = $a_root;
     }
 
-    /**
-     * @return int
-     */
-    protected function getRootId()
+    protected function getRootId() : int
     {
         return $this->root_id
             ?: $this->getTree()->readRootId();
@@ -350,7 +346,7 @@ protected function createNode(
         $nodeIconPath = $this->getNodeIcon($record);
 
         $icon = null;
-        if (is_string($nodeIconPath) && strlen($nodeIconPath) > 0) {
+        if ($nodeIconPath !== '') {
             $icon = $this->ui
                 ->factory()
                 ->symbol()
@@ -380,7 +376,7 @@ public function build(
         $node = $this->createNode($factory, $record);
 
         $href = $this->getNodeHref($record);
-        if (is_string($href) && strlen($href) > 0 && '#' !== $href) {
+        if ($href !== '' && '#' !== $href) {
             $node = $node->withLink(new \ILIAS\Data\URI(ILIAS_HTTP_PATH . '/' . $href));
         }
 
@@ -391,8 +387,8 @@ public function build(
         $nodeStateToggleCmdClasses = $this->getNodeStateToggleCmdClasses($record);
         $cmdClass = end($nodeStateToggleCmdClasses);
 
-        if (is_string($cmdClass) && strlen($cmdClass) > 0) {
-            $node = $node->withAdditionalOnLoadCode(function ($id) use ($record, $nodeStateToggleCmdClasses, $cmdClass) {
+        if (is_string($cmdClass) && $cmdClass !== '') {
+            $node = $node->withAdditionalOnLoadCode(function ($id) use ($record, $nodeStateToggleCmdClasses, $cmdClass) : string {
                 $serverNodeId = $this->getNodeId($record);
 
                 $this->ctrl->setParameterByClass($cmdClass, 'node_id', $serverNodeId);
@@ -423,7 +419,7 @@ public function getTreeComponent() : Tree
         );
 
         $label = $this->getTreeLabel();
-        if ($this->getTreeLabel() == "" && $this->getNodeContent($this->getRootNode())) {
+        if ($this->getTreeLabel() === "" && $this->getNodeContent($this->getRootNode())) {
             $label = $this->getNodeContent($this->getRootNode());
         }
 
diff --git a/Services/UIComponent/Glyph/classes/class.ilGlyphGUI.php b/Services/UIComponent/Glyph/classes/class.ilGlyphGUI.php
index 49dadc6f2ef9..9a8804e2d24d 100644
--- a/Services/UIComponent/Glyph/classes/class.ilGlyphGUI.php
+++ b/Services/UIComponent/Glyph/classes/class.ilGlyphGUI.php
@@ -61,9 +61,9 @@ public static function get(
 
         $lng = $DIC->language();
 
-        $text = ($a_text == "")
+        $text = ($a_text === "")
             ? $lng->txt(self::$map[$a_glyph]["txt"])
-            : (($a_text == self::NO_TEXT)
+            : (($a_text === self::NO_TEXT)
                 ? ""
                 : $a_text);
         switch ($a_glyph) {
diff --git a/Services/UIComponent/GroupedList/classes/class.ilGroupedListGUI.php b/Services/UIComponent/GroupedList/classes/class.ilGroupedListGUI.php
index 1cbafc6586d5..07758ddbae82 100644
--- a/Services/UIComponent/GroupedList/classes/class.ilGroupedListGUI.php
+++ b/Services/UIComponent/GroupedList/classes/class.ilGroupedListGUI.php
@@ -174,13 +174,13 @@ public function getHTML() : string
             $tpl->touchBlock("multi_end");
         }
         
-        if ($tt_calls != "") {
+        if ($tt_calls !== "") {
             $tpl->setCurrentBlock("script");
             $tpl->setVariable("TT_CALLS", $tt_calls);
             $tpl->parseCurrentBlock();
         }
 
-        if ($this->id != "") {
+        if ($this->id !== "") {
             $tpl->setCurrentBlock("id");
             $tpl->setVariable("ID", $this->id);
             $tpl->parseCurrentBlock();
diff --git a/Services/UIComponent/Lightbox/classes/class.ilLightboxGUI.php b/Services/UIComponent/Lightbox/classes/class.ilLightboxGUI.php
index 9a272e0498ba..5b693531c36f 100644
--- a/Services/UIComponent/Lightbox/classes/class.ilLightboxGUI.php
+++ b/Services/UIComponent/Lightbox/classes/class.ilLightboxGUI.php
@@ -60,7 +60,7 @@ public function addLightbox(\ilGlobalTemplateInterface $a_tpl = null) : void
     {
         $tpl = $this->tpl;
         
-        if ($a_tpl == null) {
+        if ($a_tpl === null) {
             $a_tpl = $tpl;
         }
 
@@ -73,7 +73,7 @@ public function getHTML() : string
         $tpl = new ilTemplate("tpl.lightbox.html", true, true, "Services/UIComponent/Lightbox");
         $tpl->setVariable("LIGHTBOX_CONTENT", "");
         $tpl->setVariable("ID", $this->getId());
-        if ($this->getWidth() != "") {
+        if ($this->getWidth() !== "") {
             $tpl->setVariable("WIDTH", "width: " . $this->getWidth() . ";");
         }
         return $tpl->get();
diff --git a/Services/UIComponent/Modal/classes/class.ilModalGUI.php b/Services/UIComponent/Modal/classes/class.ilModalGUI.php
index 61decb007c7a..85d25bcd7f2f 100644
--- a/Services/UIComponent/Modal/classes/class.ilModalGUI.php
+++ b/Services/UIComponent/Modal/classes/class.ilModalGUI.php
@@ -136,11 +136,7 @@ public static function initJS(ilGlobalTemplateInterface $a_main_tpl = null) : vo
     {
         global $DIC;
 
-        if ($a_main_tpl != null) {
-            $tpl = $a_main_tpl;
-        } else {
-            $tpl = $DIC["tpl"];
-        }
+        $tpl = $a_main_tpl ?? $DIC["tpl"];
 
         $tpl->addJavaScript("./Services/UIComponent/Modal/js/Modal.js");
     }
diff --git a/Services/UIComponent/NestedList/classes/class.ilNestedList.php b/Services/UIComponent/NestedList/classes/class.ilNestedList.php
index 57539689e810..ed677a0f2942 100644
--- a/Services/UIComponent/NestedList/classes/class.ilNestedList.php
+++ b/Services/UIComponent/NestedList/classes/class.ilNestedList.php
@@ -137,7 +137,7 @@ public function renderNode(
 
     public function listItemStart(ilTemplate $tpl) : void
     {
-        if ($this->getItemClass() != "") {
+        if ($this->getItemClass() !== "") {
             $tpl->setCurrentBlock("list_item_start");
             $tpl->setVariable("LI_CLASS", ' class="' . $this->getItemClass() . '" ');
             $tpl->parseCurrentBlock();
@@ -157,11 +157,11 @@ public function listStart(ilTemplate $tpl, int $depth) : void
     {
         //echo "<br>listStart";
 
-        $class = ($this->getListClass($depth) != "")
+        $class = ($this->getListClass($depth) !== "")
             ? $this->getListClass($depth)
             : $this->getListClass();
         //echo "-$class-";
-        if ($class != "") {
+        if ($class !== "") {
             $tpl->setCurrentBlock("list_start");
             $tpl->setVariable("UL_CLASS", ' class="' . $class . '" ');
             $tpl->parseCurrentBlock();
diff --git a/Services/UIComponent/Overlay/classes/class.ilOverlayGUI.php b/Services/UIComponent/Overlay/classes/class.ilOverlayGUI.php
index c805cb06779b..e7bacd9e106c 100644
--- a/Services/UIComponent/Overlay/classes/class.ilOverlayGUI.php
+++ b/Services/UIComponent/Overlay/classes/class.ilOverlayGUI.php
@@ -112,15 +112,15 @@ public function getOnLoadCode() : string
         // yui cfg string
         $yuicfg["visible"] = $this->visible;
         
-        if ($this->width != "") {
+        if ($this->width !== "") {
             $yuicfg["width"] = $this->width;
         }
         
-        if ($this->height != "") {
+        if ($this->height !== "") {
             $yuicfg["height"] = $this->height;
         }
         $yuicfg["fixedcenter"] = $this->fixed_center;
-        if ($this->anchor_el_id != "") {
+        if ($this->anchor_el_id !== "") {
             $yuicfg["context"] = array($this->anchor_el_id, $this->anchor_ov_corner,
                     $this->anchor_anch_corner, array("beforeShow", "windowResize"));
         }
diff --git a/Services/UIComponent/Panel/classes/class.ilPanelGUI.php b/Services/UIComponent/Panel/classes/class.ilPanelGUI.php
index a990b3b8fc94..b5b657b58fc3 100644
--- a/Services/UIComponent/Panel/classes/class.ilPanelGUI.php
+++ b/Services/UIComponent/Panel/classes/class.ilPanelGUI.php
@@ -107,7 +107,7 @@ public function getHTML() : string
         $tpl = new ilTemplate("tpl.panel.html", true, true, "Services/UIComponent/Panel");
 
         $head_outer_div_style = "";
-        if ($this->getHeading() != "") {
+        if ($this->getHeading() !== "") {
             $tpl->setCurrentBlock("heading");
             $tpl->setVariable("HEADING", $this->getHeading());
 
@@ -129,7 +129,7 @@ public function getHTML() : string
 
         $tpl->setVariable("BODY", $this->getBody());
         
-        if ($this->getFooter() != "") {
+        if ($this->getFooter() !== "") {
             $tpl->setCurrentBlock("footer");
             $tpl->setVariable("FOOTER", $this->getFooter());
             
diff --git a/Services/UIComponent/ProgressBar/classes/class.ilProgressBar.php b/Services/UIComponent/ProgressBar/classes/class.ilProgressBar.php
index 64106473941e..ff49f6613b83 100644
--- a/Services/UIComponent/ProgressBar/classes/class.ilProgressBar.php
+++ b/Services/UIComponent/ProgressBar/classes/class.ilProgressBar.php
@@ -147,7 +147,7 @@ public function render() : string
             $tpl->touchBlock("hide_caption_out_bl");
         }
         
-        if (strlen($this->ajax_url) and $this->ajax_timeout) {
+        if ($this->ajax_url !== '' && $this->ajax_timeout) {
             $tpl->setCurrentBlock('async_status');
             $tpl->setVariable('ASYNC_STATUS_ID', $this->unique_id);
             $tpl->setVariable('ICON_OK', ilUtil::getImagePath('icon_ok.svg'));
diff --git a/Services/UIComponent/Tabs/classes/class.ilTabsGUI.php b/Services/UIComponent/Tabs/classes/class.ilTabsGUI.php
index 143d76a0bc5d..0e59dd4f5730 100755
--- a/Services/UIComponent/Tabs/classes/class.ilTabsGUI.php
+++ b/Services/UIComponent/Tabs/classes/class.ilTabsGUI.php
@@ -256,9 +256,9 @@ public function addSubTab(
     public function setTabActive(string $a_id) : void
     {
         foreach ($this->target as $key => $target) {
-            $this->target[$key]['activate'] = $this->target[$key]['id'] == $a_id;
+            $this->target[$key]['activate'] = $this->target[$key]['id'] === $a_id;
         }
-        if ($a_id != "") {
+        if ($a_id !== "") {
             $this->manual_activation = true;
         } else {
             $this->manual_activation = false;
@@ -276,7 +276,7 @@ public function activateTab(string $a_id) : void
     public function setSubTabActive(string $a_text) : void
     {
         for ($i = 0, $iMax = count($this->sub_target); $i < $iMax; $i++) {
-            $this->sub_target[$i]['activate'] = $this->sub_target[$i]['id'] == $a_text;
+            $this->sub_target[$i]['activate'] = $this->sub_target[$i]['id'] === $a_text;
         }
         $this->subtab_manual_activation = true;
     }
@@ -370,12 +370,12 @@ private function __getHTML(
             $pre = $pre2 = "";
 
             // back 2 tab
-            if ($this->back_2_title != "") {
+            if ($this->back_2_title !== "") {
                 $tpl->setCurrentBlock("back_2_tab");
                 $tpl->setVariable("BACK_2_ICON", ilGlyphGUI::get(ilGlyphGUI::PREVIOUS, ilGlyphGUI::NO_TEXT));
                 $tpl->setVariable("BACK_2_TAB_LINK", $this->back_2_target);
                 $tpl->setVariable("BACK_2_TAB_TEXT", $this->back_2_title);
-                if ($this->back_2_frame != "") {
+                if ($this->back_2_frame !== "") {
                     $tpl->setVariable("BACK_2_TAB_TARGET", ' target="' . $this->back_2_frame . '" ');
                 }
 
@@ -383,12 +383,12 @@ private function __getHTML(
             }
             
             // back tab
-            if ($this->back_title != "") {
+            if ($this->back_title !== "") {
                 $tpl->setCurrentBlock("back_tab");
                 $tpl->setVariable("BACK_ICON", ilGlyphGUI::get(ilGlyphGUI::PREVIOUS, ilGlyphGUI::NO_TEXT));
                 $tpl->setVariable("BACK_TAB_LINK", $this->back_target);
                 $tpl->setVariable("BACK_TAB_TEXT", $this->back_title);
-                if ($this->back_frame != "") {
+                if ($this->back_frame !== "") {
                     $tpl->setVariable("BACK_TAB_TARGET", ' target="' . $this->back_frame . '" ');
                 }
                 $tpl->parseCurrentBlock();
@@ -400,7 +400,7 @@ private function __getHTML(
         $i = 0;
 
         // do not display one tab only
-        if ((count($targets) > 1 || $this->force_one_tab) || ($this->back_title != "" && !$a_get_sub_tabs)
+        if ((count($targets) > 1 || $this->force_one_tab) || ($this->back_title !== "" && !$a_get_sub_tabs)
             || (count($this->non_tabbed_link) > 0 && !$a_get_sub_tabs)) {
             foreach ($targets as $target) {
                 $i++;
@@ -423,7 +423,7 @@ private function __getHTML(
                     $tabtype = $pre . "tabactive";
                 }
 
-                if ($tabtype == "tabactive" || $tabtype == "subtabactive") {
+                if ($tabtype === "tabactive" || $tabtype === "subtabactive") {
                     $tpl->setCurrentBlock("sel_text");
                     $tpl->setVariable("TXT_SELECTED", $lng->txt("stat_selected"));
                     $tpl->parseCurrentBlock();
@@ -444,7 +444,7 @@ private function __getHTML(
                 // tooltip
                 if (!$this->getSetupMode()) {
                     $ttext = $ilHelp->getTabTooltipText($target["id"]);
-                    if ($ttext != "") {
+                    if ($ttext !== "") {
                         ilTooltipGUI::addTooltip(
                             $pre . "tab_" . $target["id"],
                             $ttext,
@@ -495,7 +495,7 @@ private function __getHTML(
                     // tooltip
                     if (!$this->getSetupMode()) {
                         $ttext = $ilHelp->getTabTooltipText($link["id"]);
-                        if ($ttext != "") {
+                        if ($ttext !== "") {
                             ilTooltipGUI::addTooltip(
                                 "nontab_" . $link["id"],
                                 $ttext,
diff --git a/Services/UIComponent/TextHighlighter/classes/class.ilTextHighlighterGUI.php b/Services/UIComponent/TextHighlighter/classes/class.ilTextHighlighterGUI.php
index dffdd6388a6c..966d9e0efbf6 100644
--- a/Services/UIComponent/TextHighlighter/classes/class.ilTextHighlighterGUI.php
+++ b/Services/UIComponent/TextHighlighter/classes/class.ilTextHighlighterGUI.php
@@ -36,7 +36,7 @@ public static function highlight(
             return;
         }
         
-        if ($a_tpl == null) {
+        if ($a_tpl === null) {
             $a_tpl = $tpl;
         }
         $a_tpl->addJavaScript("./Services/UIComponent/TextHighlighter/js/ilTextHighlighter.js");
diff --git a/Services/UIComponent/Toolbar/classes/class.ilToolbarGUI.php b/Services/UIComponent/Toolbar/classes/class.ilToolbarGUI.php
index bb9c39a4e611..0a776d1b56ab 100644
--- a/Services/UIComponent/Toolbar/classes/class.ilToolbarGUI.php
+++ b/Services/UIComponent/Toolbar/classes/class.ilToolbarGUI.php
@@ -260,7 +260,7 @@ public function getGroupedItems() : array
         $groups = array();
         $group = array();
         foreach ($this->items as $item) {
-            if ($item['type'] == 'separator') {
+            if ($item['type'] === 'separator') {
                 $groups[] = $group;
                 $group = array();
             } else {
@@ -309,7 +309,7 @@ public function getHTML() : string
             }
 
             // Hide toggle button if only sticky items are in the toolbar
-            if (count($this->items) == 0) {
+            if (count($this->items) === 0) {
                 $tpl->setVariable('HIDE_TOGGLE_CLASS', ' hidden');
             }
 
@@ -442,7 +442,7 @@ public function getHTML() : string
             }
 
             // form?
-            if ($this->getFormAction() != "") {
+            if ($this->getFormAction() !== "") {
                 // #18947
                 $GLOBALS["tpl"]->addJavaScript("Services/Form/js/Form.js");
 
@@ -455,10 +455,10 @@ public function getHTML() : string
                     if ($this->multipart) {
                         $tpl->setVariable("ENC_TYPE", 'enctype="multipart/form-data"');
                     }
-                    if ($this->form_target != "") {
+                    if ($this->form_target !== "") {
                         $tpl->setVariable("TARGET", ' target="' . $this->form_target . '" ');
                     }
-                    if ($this->form_name != "") {
+                    if ($this->form_name !== "") {
                         $tpl->setVariable("FORMNAME", 'name="' . $this->getFormName() . '"');
                     }
 
@@ -470,7 +470,7 @@ public function getHTML() : string
             }
 
             // id
-            if ($this->getId() != "") {
+            if ($this->getId() !== "") {
                 $tpl->setVariable("ID", ' id="' . $this->getId() . '" ');
             }
 
diff --git a/Services/UIComponent/Tooltip/classes/class.ilTooltipGUI.php b/Services/UIComponent/Tooltip/classes/class.ilTooltipGUI.php
index 1c33f6995f39..c278f47db3ab 100755
--- a/Services/UIComponent/Tooltip/classes/class.ilTooltipGUI.php
+++ b/Services/UIComponent/Tooltip/classes/class.ilTooltipGUI.php
@@ -64,7 +64,7 @@ public static function getToolTip(
         // not needed, just make sure the position plugin is included
         //		$addstr.= ", position: {viewport: $('#fixed_content')}";
         
-        if ($a_container != "") {
+        if ($a_container !== "") {
             $addstr .= ", container: '" . $a_container . "'";
         }