Every repetition of insertion sort removes an element from the input 
data, inserting it into the correct position in the already-sorted list,
 until no input elements remain. The choice of which element to remove 
from the input is arbitrary, and can be made using almost any choice 
algorithm.
<?php
                           $num=array(1,9,3,7,8,2,5,6);
                         function insertionsort($num)
                       {
                            for ($i=0;$i<=count($num)-1;$i++)
                            {
                                 for($j=0;$j<$i;$j++)
                                   {
                                       if($num[$j]>$num[$i])
                                      {
                                       $temp=$num[$i];
                                       $num[$i]=$num[$j];
                                        $num[$j]=$temp;
                                       }
                                 }
                                //var_dump($num);
                            }
                            return $num;
                       }
                        var_dump($num);
                        var_dump(insertionsort($num));
?> 
 
 
 
array
  0 => int 1
  1 => int 9
  2 => int 3
  3 => int 7
  4 => int 8
  5 => int 2
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 9
  2 => int 3
  3 => int 7
  4 => int 8
  5 => int 2
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 3
  2 => int 9
  3 => int 7
  4 => int 8
  5 => int 2
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 3
  2 => int 7
  3 => int 9
  4 => int 8
  5 => int 2
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 3
  2 => int 7
  3 => int 8
  4 => int 9
  5 => int 2
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 2
  2 => int 3
  3 => int 7
  4 => int 8
  5 => int 9
  6 => int 5
  7 => int 6
array
  0 => int 1
  1 => int 2
  2 => int 3
  3 => int 5
  4 => int 7
  5 => int 8
  6 => int 9
  7 => int 6
array
  0 => int 1
  1 => int 2
  2 => int 3
  3 => int 5
  4 => int 6
  5 => int 7
  6 => int 8
  7 => int 9