diff --git a/index.js b/index.js
index 4adffa3..5d9e379 100644
--- a/index.js
+++ b/index.js
@@ -77,7 +77,7 @@ function mergeItems(itemType, currentItem, newItem, ignoreLocations) {
         currentItem.description = newItem.description;
     }
 
-    if (!currentItem.defaultValue && typeof newItem.defaultValue != 'undefined') {
+    if (!currentItem.defaultValue && typeof newItem.defaultValue !== 'undefined') {
         currentItem.defaultValue = newItem.defaultValue;
     }
 
@@ -87,7 +87,7 @@ function mergeItems(itemType, currentItem, newItem, ignoreLocations) {
         }
     }
 
-    if ((!currentItem.keywords || currentItem.keywords.length == 0) && newItem.keywords) {
+    if ((!currentItem.keywords || currentItem.keywords.length === 0) && newItem.keywords) {
         currentItem.keywords = newItem.keywords;
     }
 
diff --git a/lib/utils.js b/lib/utils.js
index 421e8ac..c78ac8e 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -484,7 +484,13 @@ const inferTypeFromVariableDeclaration = (variable) => {
         const typeOfValue = expressionsMap[variable.declarator.init.type] || typeof value;
 
         if (typeOfValue !== 'undefined') {
-            return { kind: 'type', text: typeOfValue, type: typeOfValue };
+            return {
+                kind: typeOfValue === 'function'
+                    ? 'function'
+                    : 'type',
+                text: typeOfValue,
+                type: typeOfValue,
+            };
         }
 
         return anyType;
diff --git a/lib/v3/script.js b/lib/v3/script.js
index 7904d7c..06582fe 100644
--- a/lib/v3/script.js
+++ b/lib/v3/script.js
@@ -81,6 +81,8 @@ class ScriptParser extends EventEmitter {
     emitDataItem(variable, parseContext, defaultVisibility, parentComment) {
         const comment = parentComment || getCommentFromSourceCode(variable.node, parseContext.sourceCode, { defaultVisibility, useLeading: true, useTrailing: false });
 
+        const inferredType = inferTypeFromVariableDeclaration(variable);
+
         /** @type {import('../../typings').SvelteDataItem} */
         const item = {
             ...comment,
@@ -88,7 +90,7 @@ class ScriptParser extends EventEmitter {
             kind: variable.kind,
             static: parseContext.scopeType === SCOPE_STATIC,
             readonly: variable.kind === 'const',
-            type: inferTypeFromVariableDeclaration(variable),
+            type: inferredType,
             importPath: variable.importPath,
             originalName: variable.originalName,
             localName: variable.localName,
@@ -98,6 +100,12 @@ class ScriptParser extends EventEmitter {
             item.defaultValue = variable.declarator.init.value;
         }
 
+        if (inferredType.type === 'function') {
+            parseAndMergeKeywords(comment.keywords, variable);
+            inferredType.params = variable.params;
+            inferredType.return = variable.return;
+        }
+
         this.attachLocationsIfRequired(item, variable, parseContext);
 
         updateType(item);
@@ -236,9 +244,9 @@ class ScriptParser extends EventEmitter {
         const variables = parseVariableDeclaration(declaration);
 
         variables.forEach((variable, index) => {
-
             if (level === 0) {
                 let _comment = comment;
+
                 if (index > 0) {
                     _comment = getCommentFromSourceCode(variable.declarator, context.sourceCode, { defaultVisibility: visibility, useLeading: true, useTrailing: false });
                 }
@@ -370,6 +378,7 @@ class ScriptParser extends EventEmitter {
                 if (node.consequent) {
                     this.parseBodyRecursively(node.consequent, parseContext, level + 1);
                 }
+
                 if (node.alternate) {
                     this.parseBodyRecursively(node.alternate, parseContext, level + 1);
                 }
diff --git a/lib/v3/v3-utils.js b/lib/v3/v3-utils.js
index d0ed079..2fd1103 100644
--- a/lib/v3/v3-utils.js
+++ b/lib/v3/v3-utils.js
@@ -54,36 +54,52 @@ function getInnermostBody(node) {
     return node;
 }
 
+/**
+ *
+ * @param {AstNode} nodeParams Array of node parameters
+ * @return {import('../../typings').SvelteMethodParamItem[]}
+ */
+function parseParams(nodeParams) {
+    /** @type {import('../../typings').SvelteMethodParamItem[]} */
+    const params = [];
+
+    if (nodeParams && nodeParams.length) {
+        nodeParams.forEach((param) => {
+            if (param.type === 'Identifier') {
+                params.push({
+                    name: param.name
+                });
+            }
+
+            if (param.type === 'AssignmentPattern') {
+                const inferredType = inferTypeFromVariableDeclaration({
+                    // fake variable declarator block
+                    declarator: {
+                        init: param.right
+                    }
+                });
+
+                params.push({
+                    name: param.left.name,
+                    type: inferredType,
+                    description: null,
+                    optional: true,
+                    defaultValue: param.right.raw,
+                });
+            }
+        });
+    }
+
+    return params;
+}
+
 /**
  * @param {AstNode} node a 'FunctionDeclaration' AST node
  */
 function parseFunctionDeclaration(node) {
     assertNodeType(node, 'FunctionDeclaration');
 
-    const params = [];
-
-    node.params.forEach((param) => {
-        if (param.type === 'Identifier') {
-            params.push({
-                name: param.name
-            });
-        }
-        if (param.type == 'AssignmentPattern') {
-            let inferred_type = inferTypeFromVariableDeclaration({
-                //fake variable declarator block
-                declarator: {
-                    init: param.right
-                }
-            });
-            params.push({
-                name: param.left.name,
-                type: inferred_type,
-                description: null,
-                optional: true,
-                defaultValue: param.right.raw
-            });
-        }
-    });
+    const params = parseParams(node.params);
 
     const output = {
         node: node,
@@ -108,9 +124,10 @@ function parseVariableDeclaration(node) {
 
     node.declarations.forEach(declarator => {
         const idNode = declarator.id;
+        const init = declarator.init;
 
         if (idNode.type === 'Identifier') {
-            result.push({
+            const data = {
                 name: idNode.name,
                 kind: node.kind,
                 node: node,
@@ -119,7 +136,20 @@ function parseVariableDeclaration(node) {
                     start: idNode.start,
                     end: idNode.end
                 }
-            });
+            };
+
+            if (
+                init &&
+                init.params &&
+                (
+                    init.type === 'FunctionExpression' ||
+                    init.type === 'ArrowFunctionExpression'
+                )
+            ) {
+                data.params = parseParams(init.params);
+            }
+
+            result.push(data);
         } else if (idNode.type === 'ObjectPattern') {
             idNode.properties.forEach(propertyNode => {
                 const propertyIdNode = propertyNode.key;
@@ -195,11 +225,11 @@ function parseAndMergeKeywords(keywords = [], event, allowToParseReturn = true)
              * present from parsing the AST node.
              */
             if (pIndex >= 0) {
-                if(
+                if (
                     parsedParam.type &&
                     event.params[pIndex].type &&
-                    parsedParam.type.text == '*'
-                ){
+                    parsedParam.type.text === '*'
+                ) {
                     /**
                      * Only `getDefaultJSDocType()` has type.text = "*"
                      * so, if parsedParams contain that, we can be sure that
diff --git a/test/svelte3/integration/data/data.export.functionExpression.svelte b/test/svelte3/integration/data/data.export.functionExpression.svelte
new file mode 100644
index 0000000..a6abdd6
--- /dev/null
+++ b/test/svelte3/integration/data/data.export.functionExpression.svelte
@@ -0,0 +1,29 @@
+<script>
+    /* Adds two numbers `a` and `b`*/
+    export let add = function(a = 0, b = 0){
+        return a + b
+    },
+    /**
+     * Subtracts two numbers `b` from `a`
+     * @param {number} a - first number
+     * @param {number} [b=0] - second number
+     * @returns {number} - the difference
+     */
+    subtract = function(a, b){
+        return a - b;
+    },
+    /**
+     * Multiplies two numbers `a` and `b`
+     * @param a - first number
+     * @param b - second number
+     * @returns {number} - the total
+     */
+    multiply = (a = 0, b = 1) => {
+        return a * b
+    };
+
+    export let done = function(){
+        //nothing happens
+    }
+
+</script>
\ No newline at end of file
diff --git a/test/svelte3/integration/data/data.spec.js b/test/svelte3/integration/data/data.spec.js
index 3bac4ec..2736508 100644
--- a/test/svelte3/integration/data/data.spec.js
+++ b/test/svelte3/integration/data/data.spec.js
@@ -209,6 +209,110 @@ describe('SvelteDoc v3 - Props', () => {
         });
     });
 
+    it('Function expression declarations should be parsed', (done) => {
+        parser.parse({
+            version: 3,
+            filename: path.resolve(__dirname, 'data.export.functionExpression.svelte'),
+            features: ['data'],
+            ignoredVisibilities: []
+        }).then((doc) => {
+            expect(doc, 'Document should be provided').to.exist;
+
+            expect(doc.data, 'Document methods should be parsed').to.exist;
+            expect(doc.data.length).to.equal(4);
+
+            const data0 = doc.data[0];
+            const data1 = doc.data[1];
+            const data2 = doc.data[2];
+            const data3 = doc.data[3];
+
+            expect(data0.name).to.equal('add');
+            expect(data0.type.type).to.equal('function');
+            expect(data0.type.kind).to.equal('function');
+            expect(data0.type.params, 'Function expression arguments should be parsed').to.exist;
+            expect(data0.description).to.equal('Adds two numbers `a` and `b`');
+
+            const data0params0 = data0.type.params[0];
+
+            expect(data0params0.name).to.equal('a');
+            expect(data0params0.description).to.be.null;
+            expect(data0params0.type.type).to.equal('number');
+            expect(data0params0.defaultValue).to.equal('0');
+            expect(data0params0.optional).to.be.true;
+
+            const data0params1 = data0.type.params[1];
+
+            expect(data0params1.name).to.equal('b');
+            expect(data0params1.description).to.be.null;
+            expect(data0params1.type.type).to.equal('number');
+            expect(data0params1.defaultValue).to.equal('0');
+            expect(data0params1.optional).to.be.true;
+
+            expect(data1.name).to.equal('subtract');
+            expect(data1.type.type).to.equal('function');
+            expect(data1.type.kind).to.equal('function');
+            expect(data1.type.params, 'Function expression arguments should be parsed').to.exist;
+            expect(data1.description).to.equal('Subtracts two numbers `b` from `a`');
+
+            const data1params0 = data1.type.params[0];
+
+            expect(data1params0.name).to.equal('a');
+            expect(data1params0.description).to.equal('first number');
+            expect(data1params0.type.type).to.equal('number');
+            expect(data1params0.defaultValue).to.be.undefined;
+            expect(data1params0.optional).to.be.false;
+
+            const data1params1 = data1.type.params[1];
+
+            expect(data1params1.name).to.equal('b');
+            expect(data1params1.description).to.equal('second number');
+            expect(data1params1.type.type).to.equal('number');
+            expect(data1params1.defaultValue).to.equal('0');
+            expect(data1params1.optional).to.be.true;
+
+            expect(data1.type.return, 'function expression return keyword should be parsed').to.exist;
+            expect(data1.type.return.type).to.exist;
+            expect(data1.type.return.type.type).to.equal('number');
+            expect(data1.type.return.description).to.equal('the difference');
+
+            expect(data2.name).to.equal('multiply');
+            expect(data2.type.type).to.equal('function');
+            expect(data2.type.params, 'Function expression arguments should be parsed').to.exist;
+            expect(data2.description).to.equal('Multiplies two numbers `a` and `b`');
+
+            const data2params0 = data2.type.params[0];
+
+            expect(data2params0.name).to.equal('a');
+            expect(data2params0.description).to.equal('first number');
+            expect(data2params0.type.type).to.equal('number');
+            expect(data2params0.defaultValue).to.equal('0');
+            expect(data2params0.optional).to.be.true;
+
+            const data2params1 = data2.type.params[1];
+
+            expect(data2params1.name).to.equal('b');
+            expect(data2params1.description).to.equal('second number');
+            expect(data2params1.type.type).to.equal('number');
+            expect(data2params1.defaultValue).to.equal('1');
+            expect(data2params1.optional).to.be.true;
+
+            expect(data2.type.return, 'function expression return keyword should be parsed').to.exist;
+            expect(data2.type.return.type).to.exist;
+            expect(data2.type.return.type.type).to.equal('number');
+            expect(data2.type.return.description).to.equal('the total');
+
+            expect(data3.name).to.equal('done');
+            expect(data3.type.type).to.equal('function');
+            expect(data3.type.kind).to.equal('function');
+            expect(data3.type.params).to.not.exist;
+            expect(data3.description).to.be.null;
+
+            done();
+        }).catch(e => {
+            done(e);
+        });
+    });
+
     it('Imported default data should be parsed with comment', (done) => {
         parser.parse({
             version: 3,
@@ -436,10 +540,11 @@ describe('SvelteDoc v3 - Props', () => {
             expect(localProp, 'Local prop definition also must be provided').to.exist;
 
             const prop2 = doc.data.find(d => d.name === 'switch');
+
             expect(prop2).to.exist;
             expect(prop2.name, 'Aliace name must be exposed instead of original name').to.equal('switch');
             expect(prop2.localName, 'Local name must be stored').to.equal('switchValue');
-            expect(prop2.defaultValue).to.equal("main");
+            expect(prop2.defaultValue).to.equal('main');
             expect(prop2.keywords).to.exist;
             expect(prop2.keywords.length).to.equal(1);
 
diff --git a/test/svelte3/integration/events/events.spec.js b/test/svelte3/integration/events/events.spec.js
index 17a540a..73f4891 100644
--- a/test/svelte3/integration/events/events.spec.js
+++ b/test/svelte3/integration/events/events.spec.js
@@ -109,21 +109,25 @@ describe('SvelteDoc v3 - Events', () => {
             expect(location, 'Location should be correct identified').is.deep.equals({ start: 122, end: 130 });
 
             const event1 = doc.events[1];
+
             expect(event1, 'Event should be a valid entity').to.exist;
             expect(event1.name).to.equal('start');
             expect(event1.visibility).to.equal('public');
 
             const event2 = doc.events[2];
+
             expect(event2, 'Event should be a valid entity').to.exist;
             expect(event2.name).to.equal('end');
             expect(event2.visibility).to.equal('public');
 
-            const event3= doc.events[3];
+            const event3 = doc.events[3];
+
             expect(event3, 'Event should be a valid entity').to.exist;
             expect(event3.name).to.equal('running');
             expect(event3.visibility).to.equal('public');
 
             const event4 = doc.events[4];
+
             expect(event4, 'Event should be a valid entity').to.exist;
             expect(event4.name).to.equal('failed');
             expect(event4.visibility).to.equal('public');
diff --git a/typings.d.ts b/typings.d.ts
index 320197f..131f8f5 100644
--- a/typings.d.ts
+++ b/typings.d.ts
@@ -14,7 +14,19 @@ export interface JSDocKeyword {
     description: string;
 }
 
+export type JSDocTypeKind = 'type' | 'const' | 'union' | 'function';
+
 export interface JSDocTypeBase {
+    /**
+     * The kind of JSDocType object.
+     * That property can identify which additional properties included in that object.
+     * 
+     * @see JSDocTypeElement
+     * @see JSDocTypeConst
+     * @see JSDocTypeUnion
+     * @see JSDocTypeFunction
+     */
+    kind: JSDocTypeKind;
     /**
      * The text representation of this type.
      */
@@ -63,7 +75,26 @@ export interface JSDocTypeUnion extends JSDocTypeBase {
     type: JSDocType[];
 }
 
-export type JSDocType = JSDocTypeElement | JSDocTypeConst | JSDocTypeUnion;
+export interface IMethodDefinition {
+    /**
+     * The list of parameter items of the function expression.
+     */
+    params?: SvelteMethodParamItem[];
+    /**
+      * The return item of the function expression. This exists if an item with 'name' equal
+      * to 'returns' or 'return' exists in 'keywords'.
+      */
+    return?: SvelteMethodReturnItem;
+}
+
+/**
+ * @since {4.2.0}
+ */
+export interface JSDocTypeFunction extends JSDocTypeBase, IMethodDefinition {
+    kind: 'function';    
+}
+
+export type JSDocType = JSDocTypeElement | JSDocTypeConst | JSDocTypeUnion | JSDocTypeFunction;
 
 /**
  * Represents a source location of symbol.
@@ -244,19 +275,7 @@ export interface SvelteMethodReturnItem {
     description?: string;
 }
 
-export interface SvelteMethodItem extends ISvelteItem {
-    /**
-     * The list of parameter items of the method.
-     * @since {4.0.0}
-     */
-    params?: SvelteMethodParamItem[];
-
-    /**
-     * The return item of the method. This exists if an item with 'name' equal
-     * to 'returns' or 'return' exists in 'keywords'.
-     * @since {4.0.0}
-     */
-    return?: SvelteMethodReturnItem;
+export interface SvelteMethodItem extends ISvelteItem, IMethodDefinition {
 }
 
 export interface SvelteComponentItem extends ISvelteItem {