JavaScript-Practice/2 variables Differences.html at main · BhargavSandanala/JavaScript-Practice · GitHub

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<!-- 1st Var -->
<script>
    var y="bhargav";
    document.write(y + "\n");
    {
        var y=543;
        document.write(y + "\n");
    }
    document.write(y + "\n");

//    output:bhargav 543 543
</script>

<!-- 2nd Const -->
<script>
    const x='hello';
    document.write(x + "\n");
    {
        const x='namaste';
        document.write(x + "\n");
    }
    document.write(x + "\n");

    // output:hello namaste hello
</script>


<!-- 3rd example -->
<script>
    const author='bhargav';
    document.write(author);
    {
        let author='sandanala';
        document.write(author);
    }
    document.write(author);

    // output:prints nothing
</script>


<!-- 4th example -->
<script>
    const author='bhargav';
    console.log(author);
    {
        var author='bodybuilder';
        console.log(author);
    }
    console.log(author);

// output:Uncaught SyntaxError: Identifier 'author' has already been declared
</script>


<!-- 5th example -->
<script>
    const gothamCity;
    document.write(gothamCity);

    // output:Uncaught SyntaxError: Missing initializer in const declaration
</script>


<!-- Example 6 -->
<script>
let a = 543;
console.log(a);
let a="bhargav";
console.log(a);
// output:Uncaught SyntaxError: Identifier 'a' has already been declared
</script>

<!-- but the same identifier when enclosed in closure produces no Error -->
<script>
let a = 543;
console.log(a);
{let a="bhargav";
console.log(a);
}

// output:543 bhargav
</script>