Bubble algorithm gives 0~9 random n-bit number sorting

<?php

Generates a random number of 5-bit 0~9
function Getrand ($begin =0, $end =9, $limit =5) {
$rand _array=range ($begin, $end);
Shuffle ($rand _array);//Call out-of-box array random permutation function
Return Array_slice ($rand _array,0, $limit);//$limit before intercept

}

$arr = Getrand ();
$str = Implode (' ', $arr);
Echo $str;

Using bubbling algorithm to sort from small to large

Calculates the length of the array;
$length =count ($arr);
Outer Loop n-1
for ($n =0; $n < $length-1; $n + +) {
Inner-layer Cyclic n-i-1
for ($i =0; $i < $length-$n-1; $i + +) {
Determine the size of array elements, swap locations, and achieve a large order from small
if ($arr [$i]> $arr [$i +1]) {
$temp = $arr [$i +1];
$arr [$i +1]= $arr [$i];
$arr [$i]= $temp;
}
}
}

$str = Implode (' ', $arr);

Echo $str;

Bubble algorithm gives 0~9 random n-bit number sorting