选择排序

 $nums = [4, 5, 6, 3, 2, 1];
 for($i=0;$i<count($nums);$i++){
 	$min = $i;
 	for($j=$i+1;$j<count($nums);$j++){
 		if($nums[$j] < $nums[$min]){
 			$min = $j;
 		}
 	}
 	if($min != $i){
 		$tmp = $nums[$i];
 		$nums[$i]=$nums[$min];
 		$nums[$min]=$tmp;
 	}
 }
 print_r($nums);