String substring()

substring() methods return a substring and accepts either one or two arguments.

The first argument is the starting position. The second argument tells where to stop(exclusive). If the second argument is omitted, it is default to ending of the string.

substring() does not alter the value of the string itself.

 
<!DOCTYPE html>
<html>
<head>
    <title>Example</title>
    <script type="text/javascript">
    
        var stringValue = "hello world"; 
        
        document.writeln(stringValue.substring(3)); //"lo world" 
        document.writeln(stringValue.substring(3,7)); //"lo w" 

       
    </script>
</head>
<body>
</body>
</html>

Click to view the demo

All negative numbers are converted to 0.

 
<!DOCTYPE html>
<html>
<head>
    <title>Example</title>
    <script type="text/javascript">
        var stringValue = "hello world"; 
        
        document.writeln(stringValue.substring(-3)); //"hello world" 
        document.writeln(stringValue.substring(3, -4)); //"hel" 
       
    </script>
</head>
<body>
</body>
</html>

Click to view the demo