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Ryan Hellerud
3,635 Pointscall back function and changestate event question
so the video talks about setting a call back function and also claims every time there is a state change it will call said function, does it not matter where the function is placed or if the function comes after the xhr.send(). Does the browser simple update the statechange property every change and check the call back function each time?
2 Answers
Hugo Paz
15,622 PointsHi Ryan,
Every time the readyState changes, the onreadystatechange event is triggered, calling the callback function.
Because onreadystatechange is an event, the code won't get invoked until the ready state changes, which will occur at some point in the future when the request is complete.
Ryan Hellerud
3,635 Pointsinteresting, im still wrapping my brain around js events and the fact that they seems like properties but are actually events and checked when that event triggers. It is an interesting programming point that I will need to understand.
