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JavaScript AJAX Basics AJAX Concepts A Simple AJAX Example

Routine Poutine
Routine Poutine
26,050 Points

xhr.onreadystatechange vs. xhr.onload


Are these two event handlers on the xhr object the same?

a. xhr.onreadystatechange b. xhr.onload

I thought xhr.onreadystatechange also required this.status === 200, but xhr.onload only required this.readyState === 4. In this video they appear to be the same. Can I use xhr.onload for brevity?



1 Answer

Steven Parker
Steven Parker
229,732 Points

A readystatechange occurs several times in the life of a request as it progresses to different phases, but a load event only occurs when the request has successfully completed.

If you're not interested in detecting intermediate states or errors, then onload might be a good choice.

Hey Steve! Wouldn't onloadend make more sense than onload in that situation?