如何在PHP中使用另一個數組來計數數組？

Question

我有一個組數組和成員數組。 Group_one可以是會員，管理等

//groups: 
Array 
(
[0] => Array 
    (
     [id] => 1 
     ... 
     [name] => Group_one 
     ... 
    ) 
[1] => Array 
    (
     [id] => 2 
     ... 
     [name] => Group_two 
     ... 
    ) 
... 

---

//members: 
CI_DB_mysql_result Object 
(
[conn_id] => Resource id #12 
[result_id] => Resource id #55 
[result_array] => Array 
    (
     [0] => Array 
      (
       [id] => 2 
       ... 
       [group] => Group_2 
       [group_id] => 2 

      ) 
     [1] => Array 
      (
       [id] => 5 
       ... 
       [group] => Group_four 
       [group_id] => 4 

      ) 
      ... 

現在我想指望有多少Group_one，Group_two等

我嘗試以下，但無法正常工作。

foreach($groups as $group) 
{ 
    foreach ($members->result_array() as $key => $list) 
    { 
    if($group['id']==$list['group_id']) 
    { 
     $stack[] = array(); 
     array_push($stack,$list); 
    } 
    } 
} 
echo "<pre>stack is:"; 
//print_r($stack); 
echo count($stack); 
echo"</pre>end of stack"; 

Answer 1

什麼是這樣的 -

$groupCount = array(); 
foreach($groups as $group){ $groupCount[$group['id']] = 0; } 
foreach($members->result_array() as $member){ 
    $groupCount[$member['group_id']]++; 
} 

print_r($groupCount); 

1. 首先我創建和初始化一個數組來保存所有由組的每個group_id的總數。
2. 然後，我檢查每個成員，並通過成員的參數group_id增加該組的計數器。

Answer 2

也許這樣的事情會做的工作：

<?php 

$groups = array(
    array(
     "id" => 1, 
     "name" => "Group one", 
    ), 
    array(
     "id" => 2, 
     "name" => "Group two", 
    ), 
    array(
     "id" => 3, 
     "name" => "Group three", 
    ), 
); 

$members = array(
    array(
     "id" => 1, 
     "group" => "Group 1", 
     "group_id" => "1" 
    ), 
    array(
     "id" => 2, 
     "group" => "Group 1", 
     "group_id" => "1" 
    ), 
    array(
     "id" => 3, 
     "group" => "Group 2", 
     "group_id" => "2" 
    ), 
    array(
     "id" => 4, 
     "group" => "Group 2", 
     "group_id" => "2" 
    ), 
    array(
     "id" => 5, 
     "group" => "Group 2", 
     "group_id" => "2" 
    ), 
    array(
     "id" => 5, 
     "group" => "Group 3", 
     "group_id" => "3" 
    ), 
); 

$count = array(); 
foreach($members as $member){ 
    $count[$member['group_id']] = $count[$member['group_id']]+1; 
} 

var_dump($count); 
?> 

Answer 3

怎麼樣一個面向對象的結構，爲您的組和成員？我得到了這個：

<?php 

/** 
* This cass describes a single group 
*/ 
class Group { 
    private $id; 
    public $name; 
    private $members; 

    /** 
    * @param int $id 
    * @param string $name 
    */ 
    public function __construct($id, $name) { 
     $this->id = $id; 
     $this->name = $name; 
    } 

    /** 
    * Add a member to the list 
    * @param Member $member 
    */ 
    public function add_member(Member $member) { 
     $this->members[$member->get_ID()] = $member; 
     $member->associate_group($this); 
    } 

    /** 
    * Remove a member from the list 
    * @param Member $member 
    * @throws Exception in case of Member not existing. 
    */ 
    public function remove_member(Member $member) { 
     if (!in_array($member, $this->members, true)) { 
      throw new Exception("Member is not found in this group!"); 
     } 
     unset($this->members[$member->get_ID()]); 
    } 

    public function count_members() { 
     return count($this->members); 
    } 
} 

class Member { 
    private $id; 
    private $group; 

    /** 
    * @param int $id 
    */ 
    public function __construct($id) { 
     $this->id = $id; 
    } 

    /** 
    * Associate this member with a group 
    * @param Group $group 
    */ 
    public function associate_group(Group $group) { 
     $this->group = $group; 
    } 

    public function get_group() { 
     return $this->group; 
    } 

    public function get_ID() { 
     return $this->id; 
    } 
} 

//Now to Action! 
/** @var $groups Group[] */ 
$groups = array(
    new Group(1, "Group One"), 
    new Group(2, "Group Two"), 
    new Group(3, "Group Three"), 
    new Group(4, "Group Four"), 
); 
$count = array(); 

//This would probably be called from within a loop iterating over database results 
$groups[0]->add_member(new Member(1)); 
$groups[0]->add_member(new Member(2)); 
$groups[1]->add_member(new Member(3)); 
$groups[2]->add_member(new Member(4)); 
$groups[3]->add_member(new Member(5)); 
$groups[3]->add_member(new Member(6)); 
$groups[3]->add_member(new Member(7)); 

var_dump($groups); 

//Good! Now all we need to do is count the members 
foreach($groups as $group) { 
    $count[$group->name] = $group->count_members(); 
} 

print_r($count);