Let and Const Variable tutorial in Advance JavaScript

October 14, 2024

<!DOCTYPE html>

<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Let Const Variable tutorial Advance JavaScript</title>
    <link rel="stylesheet" href="">
</head>

<body>
    <script>
        //var
        var a = "Hello<br>";
        var a = "World<br>";    //We can redeclare variable value with "var"
        a = "How are you ?<br>";    //We can reassign variable value with "var"
        document.write(a);

        //The Scope of variable with "var" is Globally
        if (1 == 1) {
            var b = "Hello var brother<br>";
        }
        document.write(b);

        for (var c = 1; c <= 5; c++) {
            document.write(c + "<br>");
        }
        document.write(c + "<br><br>");

        //let
        let a2 = "Hello<br>";
        // let a2 = "World<br>";    //We can not redeclare variable value with "let"
        a2 = "How are you ?<br>";   //We can reassign variable value with "let"
        document.write(a2);

        // The Scope of variable with "let" is Block Scope
        if (1 == 1) {
            let b2 = "Hello let brother<br><br>";
            document.write(b2);
        }
        document.write(b2);

        // for(let c2=11;c2<=15;c2++) {
        //     document.write(c2 + "<br>");
        // }
        // document.write(c2);

        //const
        const a3 = "Hello<br><br>";
        // const a3 = "World<br>";  //We can not redeclare variable value with "const"
        // a3 = "How are you ?<br><br>";    //We can not reassign variable value with "const"
        document.write(a3);

        if (1 == 1) {
            const b3 = "Hello const brother<br><br>";
            document.write(b3);
        }
        document.write(b3);

        for (const c3 = 21; c3 <= 25; c3++) {
            document.write(c3 + "<br>");
        }
        document.write(c3);
    </script>
</body>

</html>