Left Shifting an array of ints
Your current solution is actually pretty good, conceptually. There's nothing wrong with the start variable. I am not sure why you want to remove it. The loop is logically a good solution, but there's a better way than that, though (better because you can make the system do it for you....).

public int[] shiftLeft(int[] nums) {
    if (nums == null || nums.length &lt;= 1) {
        return nums;
    }
    int start = nums[0];
    System.arraycopy(nums, 1, nums, 0, nums.length - 1);
    nums[nums.length - 1] = start;
    return nums;
}


Note that, in addition to using System.arraycopy I also check to see that the input has valid values available....