In HTML, the usage of this is "this. element" or "a certain method (this)", etc.; this pointer will automatically bind the current tag to the js function, thus binding the js function to the current tag. Set a unique ID to reduce the generation of duplicate codes.
The operating environment of this tutorial: Windows 7 system, CSS3&&HTML5 version, Dell G3 computer.
In the front-end page, when we need to bind an event to the current label, the general idea is to bind a unique id to it, but when the amount of our code is relatively large, the id Naming will become very difficult, and a js event must be written for each element. This will occur due to code duplication. The emergence of this pointer solves this phenomenon. It will automatically bind the current tag to the js function, as shown below This is an example:
Realize the color change when the mouse is placed on the div block:
<html> <head> </head> <body> <div style="width:300px;height:300px;background:#aaa;display:block;" onmouseover="show(this)" onmouseout="mOut(this)"></div> <script> function show(obj){ obj.style.background="#faa"; } function mOut(obj){ obj.style.background="#aaa"; } </script> </body> </html>
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