How to use void keyword in JavaScript?

Javascript Web Development Front End Technology

The void is an important keyword in JavaScript, which can be used as a unary operator that appears before its single operand, which may be of any type. This operator specifies an expression to be evaluated without returning a value.

The syntax of the void can be either of the following two −

<head>
   <script>
      <!--
         void func()
         javascript:void func()
         or:
         void(func())
         javascript:void(func())
      //-->
   </script>
</head>

The most common use of this operator is in a client-side javascript: URL, where it allows you to evaluate an expression for its side-effects without the browser displaying the value of the evaluated expression.

Here the expression alert ('Warning!!!') is evaluated but it is not loaded back into the current document.

Example

Live Demo

<html>
   <head>
      <script>
         <!--
            //-->
      </script>
   </head>
   <body>
      <p>Click the following, This won't react at all...</p>
      <a href="javascript:void(alert('Warning!!!'))">Click me!</a>
   </body>
</html>

Seetha

Published on 03-Feb-2018 09:42:36

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