PHP实现数组的笛卡尔积运算示例
这篇文章主要介绍了PHP实现数组的笛卡尔积运算,结合实例形式分析了php数组的笛卡尔积运算相关实现与使用技巧,需要的朋友可以参考下。
本文实例讲述了PHP实现数组的笛卡尔积运算,分享给大家供大家参考,具体如下:
数组的笛卡尔积在实际中还是挺有用处的,比如计算商品的规格时就经常用到,下面写一种实现方式,如下代码
- $arr = array(
- array(2),
- array(6,7),
- array('a','b','c')
- );
- function dikaer($arr){
- $arr1 = array();
- $result = array_shift($arr);
- while($arr2 = array_shift($arr)){
- $arr1 = $result;
- $result = array();
- foreach($arr1 as $v){
- foreach($arr2 as $v2){
- if(!is_array($v))$v = array($v);
- if(!is_array($v2))$v2 = array($v2);
- $result[] = array_merge_recursive($v,$v2);
- }
- }
- }
- return $result;
- }
以上例子输出的结果如下:
- Array
- (
- [0] => Array
- (
- [0] => 2
- [1] => 6
- [2] => a
- )
- [1] => Array
- (
- [0] => 2
- [1] => 6
- [2] => b
- )
- [2] => Array
- (
- [0] => 2
- [1] => 6
- [2] => c
- )
- [3] => Array
- (
- [0] => 2
- [1] => 7
- [2] => a
- )
- [4] => Array
- (
- [0] => 2
- [1] => 7
- [2] => b
- )
- [5] => Array
- (
- [0] => 2
- [1] => 7
- [2] => c
- )
- )
如果需要输出字符串形式的结果可以把代码改成这样
- function dikaer($arr){
- $arr1 = array();
- $result = array_shift($arr);
- while($arr2 = array_shift($arr)){
- $arr1 = $result;
- $result = array();
- foreach($arr1 as $v){
- foreach($arr2 as $v2){
- $result[] = $v.','.$v2;
- }
- }
- }
- return $result;
- }
输出结果如下所示:
- Array
- (
- [0] => 2,6,a
- [1] => 2,6,b
- [2] => 2,6,c
- [3] => 2,7,a
- [4] => 2,7,b
- [5] => 2,7,c
- )