array_multisort() can be used to sort several arrays at once, or a multi-dimensional array by one or more dimensions.
Associative (string) keys will be maintained, but numeric keys will be re-indexed.
The input arrays are treated as columns of a table to be sorted by rows - this resembles the functionality of SQL ORDER BY clause. The first array is the primary one to sort by. The rows (values)
in that array that compare the same are sorted by the next input array, and so on.
The argument structure of this function is a bit unusual, but flexible. The first argument has to be an array. Subsequently, each argument can be either an array or a sorting flag from the
Sorting order flags:
SORT_ASC - Sort in ascending order
SORT_DESC - Sort in descending order
Sorting type flags:
SORT_REGULAR - Compare items normally
SORT_NUMERIC - Compare items numerically
SORT_STRING - Compare items as strings
No two sorting flags of the same type can be specified after each array. The sorting flags specified after an array argument apply only to that array - they are reset to default SORT_ASC and SORT_REGULAR before each new array argument.
In this example, after sorting, the first array will contain "10", "a", 100, 100. The second array will contain 1, 1, "2", 3. The entries in the second array corresponding to the identical entries
in the first array (100 and 100) were sorted as well.
In this example, after sorting, the first array will contain "10", 100, 100, "a" (it was sorted as strings in ascending order). The second will contain 1, 3, "2", 1 (sorted as numbers, in