In Insertion Sort ,If it is the first element, it is already sorted.Pick next element and compare with all other elements.And Shift all the elements in the sorted sub-list that is greater than the value to be sorted.Repeat the process untill sorted.

<?php
$unsorted_numbers = array(3,7,1,26,43,12,6,21,23,73);
function insertionsort($array)
{
for ($i = 0; $i < count($array); $i++) {
$val = $array[$i];
$j = $i-1;
while($j>=0 && $array[$j] > $val){
$array[$j+1] = $array[$j];
$j--;
}
$array[$j+1] = $val;
}
return $array;
}
$sorted_numbers = insertionsort($unsorted_numbers);
print_r($sorted_numbers);

## Output :

Array
(
[0] => 1
[1] => 3
[2] => 6
[3] => 7
[4] => 12
[5] => 21
[6] => 23
[7] => 26
[8] => 43
[9] => 73
)

## Comments :