JS dynamic insertion and immediate execution of callback functions _javascript tips

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<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">  

The dynamic insertion of JS files plays a very important role in improving page loading speed and cross domain problems. The above is a simple example.

IE support onreadystatechange, do not support onload

Firefox support onload, do not support onreadystatechange

ie above not necessarily loaded or complete trigger, or two will trigger, so use or to judge.

Note the case of Script.onreadystatechange and script.readystate, which can cause errors that are not easy to detect, case-insensitive.

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I hope this article will help you with JavaScript programming.