Hackerrank with PHP: Arrays Left Rotation

Got another simple Hackerrank solution! This is one of the first challenges in the arrays section dealing with left rotation. Here's the problem description:

A left rotation operation on an array shifts each of the array's elements 1 unit to the left. For example, if 2 left rotations are performed on array [1,2,3,4,5], then the array would become [3,4,5,1,2]

Given an array a of n integers and a number, d, perform d left rotations on the array. Return the updated array to be printed as a single line of space-separated integers.

Hope this helps! Let me know of any questions in the comments.