如何计算多维数组值？答案

【问题标题】：How to count multidimensional array values?如何计算多维数组值？
【发布时间】：2012-06-26 04:41:42
【问题描述】：

我正在用PHP构建一个传销软件，它的一个功能是统计下线表现。它从父子关系创建一个数组，如下所示。我如何才能通过第五层获得我的孩子和他们的孙子的表现（数组键：积分）？

【问题讨论】：

标签： php arrays recursion multidimensional-array

【解决方案1】：

这应该从像这样的主数组开始无限深度地工作

$array = array(
    'children' => array( /* ADD HERE INFINITE COMBINATION OF CHILDREN ARRAY */ ),
    'id' => #,
    'name' => '',
    'email' => '',
    'points' => #
);

function recursive_children_points($arr) {
    global $hold_points;
    if (isset($arr['points'])) {
        $hold_points[] = $arr['points'];
    }
    if (isset($arr['children'])) {
        foreach ($arr['children'] as $children => $child) {
            recursive_children_points($child);
        }
    }
    return $hold_points;
}

$points = recursive_children_points($array);
print "<pre>";
print_r($points);
/**
     // OUTPUT
     Array
(
    [0] => 99999
    [1] => 7
    [2] => 4
    [3] => 3
    [4] => 666
    [5] => 43
)
**/
    print "<pre>";

【讨论】：

【解决方案2】：

在我看来，这需要recursion，因为您将对数组的每个平面级别执行相同的操作：添加点。

所以你需要

循环遍历每个数组
添加点发现
如果我们找到任何孩子，请再做一次，但要使用孩子数组

同时跟踪关卡并在达到极限时跳出

考虑到这一点，我想到了以下解决方案：

<?php

$values = array();

//first
$values[] = array('name'=>'andrej','points'=>1,'children'=>array());
$values[] = array('name'=>'peter','points'=>2,'children'=>array());
$values[] = array('name'=>'mark','points'=>3,'children'=>array());

//second
$values[0]['children'][] = array('name'=>'Sarah','points'=>4,'children'=>array());
$values[2]['children'][] = array('name'=>'Mike','points'=>5,'children'=>array());

//third 
$values[0]['children'][0]['children'][] = array('name'=>'Ron','points'=>6,'children'=>array());

//fourth
$values[0]['children'][0]['children'][0]['children'][] = array('name'=>'Ronny','points'=>7,'children'=>array());

//fifth
$values[0]['children'][0]['children'][0]['children'][0]['children'][] = array('name'=>'Marina','points'=>10,'children'=>array());

//sixth
$values[0]['children'][0]['children'][0]['children'][0]['children'][0]['children'][] = array('name'=>'Pjotr','points'=>400,'children'=>array());


function collect_elements($base, $maxLevel,$child='children',$gather='points', &$catch = array(), $level = 0) {
/*    I pass $catch by reference so that all recursive calls add to the same array
      obviously you could use it straight away but I return the created array as well
  because I find it to be cleaner in PHP (by reference is rare and can lead to confusion)

  $base = array it works on
  $maxLevel = how deep the recursion goes

  $child = key of the element where you hold your possible childnodes
      $gather = key of the element that has to be collected
*/

  $level++;
  if($level > $maxLevel) return; // we're too deep, bail out

  foreach ($base as $key => $elem) {
    // collect the element if available
    if(isset($elem[$gather])) $catch[] = $elem[$gather];

    /*
    does this element's container have children? 
       [$child] needs to be set, [$child] needs to be an array, [$child] needs to have elements itself
    */
    if (isset($elem[$child]) && is_array($elem[$child]) && count($elem[$child])){
       // if we can find another array 1 level down, recurse that as well  
       collect_elements($elem[$child],$maxLevel,$child,$gather, $catch,$level); 
    }
  }
return $catch;
}

print array_sum(collect_elements($values,5)) . PHP_EOL;

collect_elements 将收集您感兴趣的元素（直到达到最大深度）并将其附加到平面数组，以便您可以在返回时对其进行操作。在这种情况下，我们执行array_sum 来获取收集到的总点数

只有第一个参数是有趣的：

collect_elements($base, $maxLevel,$child='children',$gather='points'

非可选： $base 是要处理的数组 $maxLevel 是函数需要下降到数组中的最大深度可选的： $child 定义包含当前元素（数组）的子元素的元素的键 $gather 定义了包含我们要收集的内容的元素的键

其余参数只是用于递归的参数

【讨论】：

不知道最高级别会怎样？