Move all negative elements to end in php

Php program for Move all negative elements to end. Here mentioned other language solution.

<?php
// Php program for
// Move all negative elements at the end of array
class MyArray
{
	// Display array elements
	public	function display($arr, $n)
	{
		for ($i = 0; $i < $n; $i++)
		{
			echo "  ".($arr[$i]);
		}
		print("\n");
	}
	// Swap the given array elements
	public	function swap(&$arr, $start, $end)
	{
		$temp = $arr[$start];
		$arr[$start] = $arr[$end];
		$arr[$end] = $temp;
	}
	// Method which is move negative elements
	public	function moveNegative(&$arr, $n)
	{
		// first index
		$i = 0;
		// last index
		$j = $n - 1;
		while ($i < $j)
		{
			if ($arr[$i] < 0 && $arr[$j] >= 0)
			{
				// When [i] index are have negative value 
				// And [j] is positive then swapping elements values
				$this->swap($arr, $i, $j);
				// Modified index
				$i++;
				$j--;
			}
			else if ($arr[$i] >= 0)
			{
				// When element of [i] is not negative
				$i++;
			}
			else
			{
				$j--;
			}
		}
	}
	public static function main()
	{
		$task = new MyArray();
		// Array which are containing positive and negative values
		$arr = array(1, -1, 3, 2, -7, -5, 11, 6);
		$n = count($arr);
		echo "Before Arrange : \n";
		// Before move element
		$task->display($arr, $n);
		// Move negative elements
		$task->moveNegative($arr, $n);
		// After arrange
		echo "After Arrange : \n";
		// After move element
		$task->display($arr, $n);
	}
}
MyArray::main();

Output

Before Arrange :
  1  -1  3  2  -7  -5  11  6
After Arrange :
  1  6  3  2  11  -5  -7  -1