在做商品屬性時設計到多個屬性直接引數的組合，因此用到了笛卡爾積這個概念。主要函式原理是利用遞迴的原理和求兩個陣列的笛卡爾積。

首先是陣列結構，如下：也可以根據實際情況修改為$a = Array();$b=Array();即可。

array (size=2)
  0 => 
    array (size=2)
      0 =>  '48' (length=2)
      1 =>  '49' (length=2)
  1 => 
    array (size=3)
      0 =>  '51' (length=2)
      1 =>  '52' (length=2)
 

      2 =>  '53' (length=2)

所涉及到的兩個函式

//遞迴求笛卡爾積函式
public function combineDika($dikad,$dalen)
{
 $data = $dikad;
 $cnt = $dalen;  
 $result = array();
 foreach($data[0] as $item) {
 $result[] = array($item);
 }
 for($i = 1; $i < $cnt; $i++) {
 $result = $this->combineArray($result,$data[$i]);
 }
 return $result;
}

//求兩個陣列的笛卡爾積
function combineArray($arr1,$arr2)
 { 
     $result = array();
     foreach ($arr1 as $item1) {
        foreach ($arr2 as $item2) {
            $temp = $item1;
            $temp[] = $item2;
            $result[] = $temp;
        }
  }
    return $result;
   }

執行結果：

array (size=6)
  0 => 
    array (size=2)
      0 =>  '48' (length=2)
      1 =>  '51' (length=2)
  1 => 
    array (size=2)
      0 =>  '48' (length=2)
      1 =>  '52' (length=2)
  2 => 
    array (size=2)
      0 =>  '48' (length=2)
      1 =>  '53' (length=2)
  3 => 
    array (size=2)
      0 =>  '49' (length=2)
      1 =>  '51' (length=2)
  4 => 
    array (size=2)
      0 =>  '49' (length=2)
      1 =>  '52' (length=2)
  5 => 
    array (size=2)
      0 =>  '49' (length=2)
      1 =>  '53' (length=2)