Sort arrays destructively.
This function sorts the array index destructively. That means
that the array itself is changed and returned, no copy is created.
If extra arguments are given, they are supposed to be arrays of the
same size as index . Each of these arrays will be modified in the
same way as index . I.e. if index 3 is moved to position 0 in index
index 3 will be moved to position 0 in all the other arrays as well.
sort() can sort strings, integers and floats in ascending order.
Arrays will be sorted first on the first element of each array.
Objects will be sorted in ascending order according to `<() , `>()
and `==() .