How to set black background in javascript

JavaScript background setting black

With the rapid development of Internet technology, Web front-end technology has increasingly become the focus of attention. Among them, JavaScript is one of the main languages ​​​​for Web front-end development, and its scope of use is becoming more and more widespread. In the process of Web page development, background setting is an indispensable link. This article will introduce how to use JavaScript to set the background of a web page to black.

JavaScript is a scripting language that can be directly embedded and executed in HTML pages. It is mainly used to add interactive and dynamic effects. In web page development, JavaScript is often used to dynamically modify CSS styles to achieve dynamic effects and interactive features of page elements. The background color is the most basic style in a Web page, so we can modify the background color through JavaScript, thereby changing the visual effect of the entire page.

How to change the background color of a Web page using JavaScript

Here we introduce the specific implementation of using JavaScript to set the background color of a Web page to black through two methods.

Method 1: Directly modify the background-color attribute value of the body

By directly modifying the background-color attribute value of the body element, we can directly change the background color of the Web page to black . The specific implementation code is as follows:

document.body.style.backgroundColor = "#000000";

This line of code will use JavaScript to directly modify the style attribute in the body element of the web page and set its background color to black. Among them, the value for setting the background color is a hexadecimal color representation, and #000000 represents black.

If you need to set the background color to another color, just replace #000000 with the hexadecimal representation of the other color. For example, if you need to set the background color to red, you can modify the code to:

document.body.style.backgroundColor = "#FF0000";

This code will set the background color of the body element to red.

Method 2: Use CSS style sheets

When organizing the styles of Web pages, we usually use CSS style sheets to manage them. Therefore, by using JavaScript to modify the style of the body element in the CSS style sheet, we can also achieve the effect of modifying the page background to black. The specific implementation code is as follows:

var style = document.createElement('style');
style.innerHTML = 'body {background-color:#000000;}';
document.head.appendChild(style);

The code here will dynamically add a style element and set the background color for the body element. The value of the innerHTML attribute of the style element is the CSS style sheet code. Similar to method 1, the background color here also uses hexadecimal notation.

It should be noted that when using this method to set the background color of the web page, flickering may occur during page rendering. This is because after adding the style element, the page will recalculate and render the style. Compared with directly modifying the body style, the execution efficiency will be slightly slower.

Summary

Through the above two methods, we can use JavaScript to dynamically modify the style of the Web page to achieve the effect of changing the background color to black. Of course, this is just a simple example. There are many other application scenarios for using JavaScript to control the style of web pages. In actual project development, we need to choose the appropriate usage method according to the actual situation in order to better improve the interactivity and user experience of the Web page.

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