1.8.1_Conditionalbranching_Tasks.html

<!DOCTYPE html>
<html>
    <head>
        <script>
           /* Task 1
           if (a string with zero)
            importance: 5
            Will alert be shown?
            */
            if ("0") 
            {
            alert( 'Hello' ); // yes, as string '0' returns true in if (not empty)
            }
            /* Task 2
            The name of JavaScript
            importance: 2
            Using the if..else construct, write the code which asks: ‘What is the “official” name of JavaScript?’
            If the visitor enters “ECMAScript”, then output “Right!”, otherwise – output: “You don’t know? ECMAScript!”
            */
           officialName = prompt('What is the “official” name of JavaScript?');
           if (officialName  == 'ECMAScript')
           {
            alert("Right!");
           }
           else
           {
            alert("You don't know?\n ECMAScript");
           }
           /* Task 3
           Show the sign
           Using if..else, write the code which gets a number via prompt and then shows in alert:

            1, if the value is greater than zero,
            -1, if less than zero,
            0, if equals zero.
            In this task we assume that the input is always a number.
            */
           let n = prompt('Enter a number:');
           if (n > 0)
           {
            alert(1);
           }
           else if (n < 0)
           {
            alert(-1);
           }
           else
           {
            alert(0); // here we have an exception if we dont give any input comparison will think it as 0, so it will alert 0
           }
           /* Task 4
           Rewrite 'if' into '?'
            importance: 5
            Rewrite this if using the conditional operator '?':

            let result;

            if (a + b < 4) {
              result = 'Below';
                            } else {
                              result = 'Over';
                                    }
            */
           let a = +prompt('Enter value of a:','');
           let b = +prompt('Enter value of b:','');
           let result;
           alert(result = (a + b < 4) ? 'Below' : 'Over');
           /* Task 5
           Rewrite if..else using multiple ternary operators '?'.

            For readability, it’s recommended to split the code into multiple lines.

            let message;

            if (login == 'Employee') 
            {
                message = 'Hello';
            } 
            else if (login == 'Director') 
            {
                message = 'Greetings';
            } 
            else if (login == '') 
            {
                message = 'No login';
            } 
            else 
            {                                                   message = '';
            }
            */
           let message;
           let login = prompt("Who is the User?");
           alert( message = (login == 'Employee')? 'Hello!': 
           (login =='Director') ? 'Greetings' :(login=="") ? "No login":'');
        </script>
    </head>
</html>