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Strict Mode In Javascript

In this article, we will discuss "strict mode" in JavaScript.

What Is Strict Mode?

In strict mode, you cannot use undeclared variables.

“use strict”

Consider the following example where we are using undeclared variables in strict mode.

<script>
    "use strict";
    try {
        pi = 3.14;

        alert(pi);
    } catch (e) {
        alert(e);
    }        
</script>

<script>
    "use strict";
    try {
      var pi = 3.14;

        alert(pi);
    } catch (e) {
        alert(e);
    }
</script>

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