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JavaScript Callback Functions in JavaScript Callbacks and the DOM Callbacks with Arguments

Posted by ammarkhan
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ammarkhan
Front End Web Development Techdegree Student 21,661 Points

Why have callback as the second argument?

In the video, Andrew made callback the second argument which is confusing for me because in setInterval or setTimeout function, the callback was the first argument the concept is little confusing for me.

2 Answers

Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

There's no specific rule for how to order arguments of a function or method. The setInterval and setTimout do similar things, and take the same type of arguments, so it makes sense they would be ordered the same way.

But the function created in the video does something entirely different from either of those, and while one argument is a callback the other is also different. So there's really no reason that the argument order should be related to either of those other functions.

darryn
darryn
17,367 Points
darryn
darryn
17,367 Points

Andrew wrote the functions in this video. So he got to choose the order of the arguments.

He didn’t write the setInterval or setTimeout methods.

Those methods are part of JavaScript and are built in for your convenience. Somebody else wrote them.