We usually use the following two methods to write css styles using js:
In general, we use js to set the style of element objects in this form:Copy codeThe Code is as follows: var element = document. getElementById ("id ");
Element. style. width = "20px ";
Element. style. height = "20px ";
Element. style. border = "solid 1px red ";
However, the above method has a disadvantage. There are many styles and a lot of code. Besides, overwriting object styles through JS is a typical process of destroying and recreating original styles, such destruction and reconstruction will increase the browser overhead.
Js has a cssText method:
Syntax: obj.style.css Text ("style ");
The above code can be modified:Copy codeThe Code is as follows: element.style.css Text = "width: 20px; height: 20px; border: solid 1px red ;";
This method can avoid multiple page reflows and improve page performance.