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| What Does JavaScript Void 0 Mean |
What Does JavaScript Void 0 Mean
JavaScript's void operator evaluates an expression and returns undefined.
Using console to verify the same :-
Note :- void irrespective of any value passed along , always returns undefined as shown above. But, void with operand 0 is preferred.
Two ways of using operand 0 -> void(0) or void 0. Either of them is fine.
When to use Javascript void (0) ?
When on link click, you don't want the browser to load a new page or refresh the same page( depending on the URL specified ). Instead,perform the JavaScript attached to that link.
Sample Example 1 with Javascript void (0) :
<html>
<body>
<a href="javascript:void(0);alert('Hello ! I am here')">Click Me</a>
</body>
</html>
Output :
When clicked on ClickMe link,an alert pops up as below :
Sample Example 2 with Javascript void (0) :
<html>
<body>
<a href="javascript:void(0)" ondblclick="alert('Hi,i didnt refresh the page')" )>Click Me</a>
</body>
</html>
Output :
When you double click the link,an alert will popup without any page refresh.
Sample Example 3 with Javascript void (0) :
<html>
<body>
<a href="javascript:void(0);https://www.google.co.in/"
ondblclick="alert('Hello !! You will see me and not get redirected to google.com ')">Click Me</a>
</body>
</html>
Output :
When you double click the link,an alert will popup,closing it will also not redirect to google.com.
Sample Example without Javascript void (0) :
<html>
<body>
<a href="https://www.google.co.in/" ondblclick="alert('Hello !! You will see me and then get redirected to google.com even if not needed')">Click Me</a>
</body>
</html>
Output :
When you double click the link,an alert will popup, closing it will redirect to google.com.
Conclusion :
void operator is useful when you need to prevent any unwanted page refresh or redirection. Rather,perform some javascript operation.