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JavaScript - Variables

Defining variables

Variables can be scoped by global or block-scoped (class, function, or namespace).

• Global variables
• Block-scoped variables

Define variable using var, let, const or nothing

JavaScript, often abbreviated as JS, is a programming language which all web developers need to learn for developing website. JavaScript is used along with HTML/CSS.

<script type="text/javascript">
    var a = '123';
    function updateA() {
        a = '234'; // Global scope
    }
    updateA();
    console.log(a);
    function updateText() {
        var a = '234'; // Function scope
    }
    updateText();
    console.log(a);
</script>