php separates array by specified number

/**
 * Separate the array by the specified number
 * @param array $array The array to be divided
 * @param int $groupNum The number of groups to be divided
*/
public function splitArray($array, $groupNum){
 if(empty($array)) return array();< ;/p>
 //Total length of the array
 $allLength = count($array);
 //Number of items
 $groupNum = intval($groupNum);< ;/p>
 //Start position
 $start = 0;
 //The number of elements in the divided array
 $enum = (int)($allLength/ $groupNum);
 //Result set
 $result = array();
 if($enum > 0){
 //Divided The part of the array that can be divided evenly into the number of elements in the array
 $firstLength = $enum * $groupNum;
 $firstArray = array();
 for($i=0; $i<$firstLength; $i++){
 array_push ($firstArray, $array[$i]);
 unset($array[$i]);
 }
 for($i=0; $i<$groupNum; $i++){
< ;p> //Truncate elements from the specified starting position and length in the original array and put them into the new array
 $result[] = array_slice($firstArray, $start, $enum);

 $start += $enum;
 }
 //The remaining parts of the array are added to the first few items of the result set respectively
 $secondLength = $allLength - $firstLength;
 for ($i=0; $i<$secondLength; $i++){
 array_push($result[$i], $array[$i + $firstLength]);
 }
 }else{
 for($i=0 ; $i<$allLength; $i++){
 $result[] = array_slice($array, $i, 1);
 }
 }
 return $result;
}