PHP基于自定义函数生成笛卡尔积的方法示例

<?php  $color = array('red', 'green');  $size = array(39, 40, 41);  $local = array('beijing', 'shanghai');  echo "<pre>";  print_r(combineDika($color, $size, $local));  /**   * 所有数组的笛卡尔积   *   * @param unknown_type $data   */  function combineDika() {    $data = func_get_args();    $cnt = count($data);    $result = array();    foreach($data[0] as $item) {      $result[] = array($item);    }    for($i = 1; $i < $cnt; $i++) {      $result = combineArray($result,$data[$i]);    }    return $result;  }  /**   * 两个数组的笛卡尔积   *   * @param unknown_type $arr1   * @param unknown_type $arr2   */  function combineArray($arr1,$arr2) {    $result = array();    foreach ($arr1 as $item1) {      foreach ($arr2 as $item2) {        $temp = $item1;        $temp[] = $item2;        $result[] = $temp;      }    }    return $result;  }?>

Array(  [0] => Array    (      [0] => red      [1] => 39      [2] => beijing    )  [1] => Array    (      [0] => red      [1] => 39      [2] => shanghai    )  [2] => Array    (      [0] => red      [1] => 40      [2] => beijing    )  [3] => Array    (      [0] => red      [1] => 40      [2] => shanghai    )  [4] => Array    (      [0] => red      [1] => 41      [2] => beijing    )  [5] => Array    (      [0] => red      [1] => 41      [2] => shanghai    )  [6] => Array    (      [0] => green      [1] => 39      [2] => beijing    )  [7] => Array    (      [0] => green      [1] => 39      [2] => shanghai    )  [8] => Array    (      [0] => green      [1] => 40      [2] => beijing    )  [9] => Array    (      [0] => green      [1] => 40      [2] => shanghai    )  [10] => Array    (      [0] => green      [1] => 41      [2] => beijing    )  [11] => Array    (      [0] => green      [1] => 41      [2] => shanghai    ))