JS Variable

Variable means which hold the data value and it can be changed anytime.

Javascript use the var keyword declare a variable.where a variable must have a unique name.

Example:-

 <script>  
var x = 5;  
var y = 5;  
var z=x+y;  
document.write(z);  
</script>    
 

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Types of variable.

There are two types of variable that is.

Local variable
Global variable.

1) Local variable in Javascript with Example

A local variable declared inside the function or block.

Example:-

  <!doctype html>    
<html>    
<head>    
    <title>Local Variable Example</title>    
</head>   
<body>    
    <script>    
        var x = 10;  // This is a Global Variable    
        function add() {    
            var y = 20; //Local variable    
            var sum = 0;//Local variable    
            for (var i = x; i < y; i++) {    
                sum = sum + i;    
                document.write(sum + "<br> ");    
             }     
            }    
           
    </script>    
    <input type="button" value="submit" onclick="add()" />    
</body>    
</html>      
 

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2) Global variable in Javascript with Example

A global variable is declared outside the function that is called Global variable.

Example:-

 <!DOCTYPE html>
<html>
<body>
<div id="test"></div>
<script>
//global variable
var a = 100;
student();
function student(){
	document.getElementById("test").innerHTML = a;
 }
</script>
</body>
</html>
 

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JS Tutorials

JS Variable

Example:-

Types of variable.

1) Local variable in Javascript with Example

Example:-

2) Global variable in Javascript with Example

Example:-