How to realize preloading Pictures by JavaScript

Editor to share with you how to achieve JavaScript preload pictures, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to understand it!

1. When the network state is not good, the target image loads slowly, and a small picture is needed to act as a placeholder.

2. Listen for the load event of the DOM, which occurs when the DOM object has been loaded.

Example

Const oImg = document.querySelector ('img'); oImg.onload = function () {this.src ='. / green.png'; this.onload = false;// to prevent repeated calls} this is all the content of the article "how to preload images in JavaScript". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!