Why would sort fail?

Question

I'm writing a library routine, which among other things will do some rather complex sorting of nested arrays.

I see from the documentation that all the array sort function (including the ones using built-in comparators) can return false on failure - but when would this ever be the case???

Answer 1

It would fail when the variable you send to the function is NOT an array
Example:

asort('Hello');//fails
asort(array(1,2,35,7,2,8,3));//true