用于比较的 PHP 高级数组循环概念 [重复]

Question

我有一个类似下面的数组...

array(2) {
  ["gender"]=>
   array(2) {
    [1]=>
    string(4) "Male"
    [2]=>
    string(6) "Female"
  }
  ["agegroup"]=>
  array(3) {
    [3]=>
    string(7) "18 - 24"
    [4]=>
    string(7) "25 - 40"
    [5]=>
    string(7) "40 - 65"
  }
}

这个数组是动态的。就像“性别”和“年龄组”一样，可以有任意数量的项目。所有这些项目都是子数组（关联）。我想在 php 中编写一个循环，该循环从第一个数组元素循环到其他数组元素中的每个元素。

In the above example... the following output should come...
Male- 18-24
Male- 25-40
Male- 40-65

FeMale- 18-24
FeMale- 25-40
FeMale- 40-65

如果数组如下...

array(2) {
  ["location"]=>
   array(2) {
    [A]=>
    string(4) "New York"
    [B]=>
    string(6) "London"
  }
  ["gender"]=>
   array(2) {
    [1]=>
    string(4) "Male"
    [2]=>
    string(6) "Female"
  }
  ["agegroup"]=>
  array(3) {
    [3]=>
    string(7) "18 - 24"
    [4]=>
    string(7) "25 - 40"
    [5]=>
    string(7) "40 - 65"
  }
}

那么...输出应该是...

New York- Male- 18-24
New York- Male- 25-40
New York- Male- 40-65

New York- FeMale- 18-24
New York- FeMale- 25-40
New York- FeMale- 40-65

London- Male- 18-24
London- Male- 25-40
London- Male- 40-65

London- FeMale- 18-24
London- FeMale- 25-40
London- FeMale- 40-65

如果定义了数组长度，我将能够使用foreach() 来编写sn-p。但是父数组和子数组的数组长度都是动态的......有人可以给我提示如何循环它以获得所需的输出吗？

Answer 1

function make ($arr, $pref = '') {            // pref - saving path to this point
 foreach (array_shift($arr) as $item)         // take the 1st item of array and remove it
   if($arr) make($arr,$pref . $item ." - ");  // Call with sub-tree, add item to path
   else echo $pref . $item ."\n";             // Empty array - we are at leaf
}

make($arr);

对于第二种情况的结果：

New York - Male - 18 - 24
New York - Male - 25 - 40
New York - Male - 40 - 65
New York - Female - 18 - 24
New York - Female - 25 - 40
New York - Female - 40 - 65
London - Male - 18 - 24
London - Male - 25 - 40
London - Male - 40 - 65
London - Female - 18 - 24
London - Female - 25 - 40
London - Female - 40 - 65