What is JavaScript void 0

"javascript:void(0)" is a specific instruction in JavaScript that evaluates to undefined. It is often used as a placeholder value in web development, particularly in event handling, to prevent the default action of an element from occurring when clicked on. For example, it can be used as the href value of an anchor tag to prevent the link from redirecting the user when clicked.

What is its use ?

The primary use of "javascript:void(0)" is to prevent an HTML element from performing its default action when clicked. For example, when used as the href value of an anchor tag, it prevents the link from redirecting the user to another page. This can be useful in cases where you want to use a link to trigger a JavaScript function instead of redirecting the user.

It is also used in javascript event handlers to prevent the default action of an element. For example, it can be used in the onclick event of a button to prevent the form submission, instead it can be used to trigger any other javascript function.

Additionally, it can also be used as a placeholder value in some JavaScript functions that expect a value to be passed to them, but you don't have a specific value to pass at the time the function is called.

It can also be used to stop the execution of script, for example, using onClick = "javascript:void(0);" in the button element to prevent the button from submitting the form when clicked.

Examples

Here are a few examples of how "javascript:void(0)" can be used:

1. In an anchor tag to prevent the link from redirecting the user:

html
<a href="javascript:void(0);" onclick="myFunction()">Click me</a>

2. In a button to prevent the form from submitting:

html
<form>
  <input type="text" name="firstname">
  <button type="submit" onclick="javascript:void(0); myFunction()">Submit</button>
</form>

3. As a placeholder value in a JavaScript function:

javascript
function myFunction(arg1 = "javascript:void(0)", arg2 = "javascript:void(0)") {
  // Do something with arg1 and arg2
}

4. To stop the execution of script:

html
<button onClick = "javascript:void(0);">Stop</button>

In this example, when the button is clicked, the script execution stops but the button click event is still handled by the browser.

It's worth noting that these are just a few examples of how "javascript:void(0)" can be used, and the specific implementation may vary depending on the context and requirements of the project.