array_pad() returns a copy of the
input
padded to size specified by
pad_size
with value
pad_value
. If
pad_size
is positive then the array is
padded on the right, if it's negative then on the left. If the
absolute value of pad_size
is less than or
equal to the length of the input
then no
padding takes place.
It is possible to add most 1048576 elements at a time.
See also array_fill() and range().