JavaScript global variable

by Online Tutorials Library July 14, 2022

JavaScript Global Variable

A JavaScript global variable is declared outside the function or declared with window object. It can be accessed from any function.

Let’s see the simple example of global variable in JavaScript.

 <script> var value=50;//global variable function a(){ alert(value); } function b(){ alert(value); } </script> 

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Declaring JavaScript global variable within function

To declare JavaScript global variables inside function, you need to use window object. For example:

Now it can be declared inside any function and can be accessed from any function. For example:

 function m(){ window.value=100;//declaring global variable by window object } function n(){ alert(window.value);//accessing global variable from other function } 

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Internals of global variable in JavaScript

When you declare a variable outside the function, it is added in the window object internally. You can access it through window object also. For example:

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