What is javascript void:0

javascript:void(0) is a pseudo-protocol for executing JavaScript code. It is often used to perform some operations without leaving the current page, such as popping up an alert box or executing other JavaScript functions. The function is to prevent the browser's default hyperlink behavior or prevent page refresh. Detailed introduction: javascript:void(0) is just a placeholder and will not perform any actual operations.

javascript:void(0) is a special JavaScript code snippet usually used in HTML as the href attribute value of a hyperlink. It's called a "pseudo-protocol" because it's not a real protocol, but a placeholder for executing JavaScript code.

In HTML, hyperlinks are often used to navigate users to other pages or resources. When a user clicks on a hyperlink, the browser loads the corresponding page based on the value of the href attribute. However, sometimes we want to execute some JavaScript code when the user clicks a link, rather than navigating to a new page. At this time, javascript:void(0) comes in handy.

The function of javascript:void(0) is to prevent the browser's default behavior, which is to perform no operation. It is a common trick used to execute some JavaScript code without leaving the current page. Usually, we put specific JavaScript code in the brackets of void(0).

For example, let's say we have a button and when the user clicks it, we want an alert box to pop up. We can write like this:

<button onclick="alert(&#39;Hello, World!&#39;)">点击我</button>

In this way, when the user clicks the button, a warning box will pop up showing "Hello, World!". However, if we put this button inside a hyperlink, and we want the same JavaScript code to execute when the user clicks the link, but not navigate to a different page, we can write like this:

<a href="javascript:void(0)" onclick="alert(&#39;Hello, World!&#39;)">点击我</a>

In this way, when the user clicks the link, a warning box will pop up showing "Hello, World!" and will not navigate to other pages.

It should be noted that javascript:void(0) is just a placeholder operator, which itself does not perform any actual operations. Its function is to tell the browser not to perform the default hyperlink behavior. If we use the void operator in JavaScript code, it will return undefined, so javascript:void(0 ) actually executes a JavaScript code that returns undefined.

In addition, javascript:void(0) can also be used to prevent page refreshes when the page jumps. In some cases, when the user clicks When a hyperlink occurs, the page will briefly refresh, which may result in a poor user experience. This refresh can be avoided by setting the href attribute of the hyperlink to javascript:void(0).

Summary Take a look, javascript:void(0) is a pseudo-protocol used to execute JavaScript code. It is often used to perform some operations without leaving the current page, such as popping up an alert box or executing other JavaScript functions. Its function is to prevent the browser from Default hyperlink behavior, or prevent page refresh .

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