What does "javascript:void(0)" mean in the href of the a tag?

The operator voidevaluates the given expression and returnsundefined

The reason for using this expression in a hrefof a linkis because this attribute causes a redirection to a plain text version of the return of the function. But if the result is undefinedthe redirect does not occur. This is the shortest way to not redirect and do nothing in a link.

Differences with other methods for not redirecting:

• href=""Reload the current page

• href="#"Scroll to the top of the page

• href="javascript: void(0)"Does nothing

• href="javascript:;"It doesn't do anything, but it doesn't work in all browsers, for example, in IE7 it redirects to a new window AND it's not as accepted as a de facto standard than the previous one

More info:

• You can find more info in this post: https://stackoverflow.com/questions/1291942/what-does-javascriptvoid0-mean
• You can find documentation at this link: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/void
• Differences: https://stackoverflow.com/questions/6968911/what-is-the-difference-between-href-href-and-href-javascriptvoid0
• Why not use href="javascript:;"? https://stackoverflow.com/questions/5237105/why-use-javascriptvoid0-instead-of-javascript-as-an-href-do-nothing-plac

The operator void, like other programming languages, defines a function that does not return a value.

In the case of Javascript: void(expresion), specifies an expression that is evaluated but will not return a value.

As an example a link that does not perform any action since it returns undefinedsince it evaluates the value of 0:

<a href="javascript:void(0)"> a) Click aquí, sin acción.</a><br>
<a href="javascript:void 0"> b) Click aquí, sin acción.</a>

Can a variable have void as its data type?

Variables in Javascript are initialized as undefined, you can't use it voidto define a data type and it's not really necessary,

example:

var myvar1;
console.log("myvar1 : " + myvar1);
var myvar2 = void 0;
console.log("myvar2 : " + myvar2);