<?php
/**
* 二維數組根據某個字段排序
* 功能：按照用戶的年齡倒序排序
* @author ruxing.li
*/
header('Content-Type:text/html;Charset=utf-8');
$arrUsers = array(
array(
'id' => 1,
'name' => '張三',
'age' => 25,
),
array(
'id' => 2,
'name' => '李四',
'age' => 23,
),
array(
'id' => 3,
'name' => '王五',
'age' => 40,
),
array(
'id' => 4,
'name' => '趙六',
'age' => 31,
),
array(
'id' => 5,
'name' => '黃七',
'age' => 20,
),
);


$sort = array(
'direction' => 'SORT_DESC', //排序順序標志 SORT_DESC 降序；SORT_ASC 升序
'field' => 'age', //排序字段
);
$arrSort = array();
foreach($arrUsers AS $uniqid => $row){
foreach($row AS $key=>$value){
$arrSort[$key][$uniqid] = $value;
}
}
if($sort['direction']){
array_multisort($arrSort[$sort['field']], constant($sort['direction']), $arrUsers);
}

var_dump($arrUsers);

/*
輸出結果：

array (size=5)
0 =>
array (size=3)
'id' => int 5
'name' => string '黃七' (length=6)
'age' => int 20
1 =>
array (size=3)
'id' => int 2
'name' => string '李四' (length=6)
'age' => int 23
2 =>
array (size=3)
'id' => int 1
'name' => string '張三' (length=6)
'age' => int 25
3 =>
array (size=3)
'id' => int 4
'name' => string '趙六' (length=6)
'age' => int 31
4 =>
array (size=3)
'id' => int 3
'name' => string '王五' (length=6)
'age' => int 40

*/