PHP 二维数组根据某个字段排序的具体实现
本文记录的要实现的功能类似于 MySQL 中的 ORDER BY，上个项目中有遇到这样的一个需求。
要求：从两个不同的表中获取各自的4条数据，然后整合(array_merge)成一个数组，再根据数据的创建时间降序排序取前4条。
遇到这个要求的时候就不是 ORDER BY 能解决的问题了。因此翻看 PHP 手册查找到了如下方法，做此笔记。
废话少说，奉上代码，清单如下：
.代码如下:
<?php
/**
* 二维数组根据某个字段排序
* 功能：按照用户的年龄倒序排序
* @author ruxing.li
*/
header('Content-Type:text/html;Charset=utf-8');
$arrUsers = array(
array(
'id' => 1,
'name' => '张三',
'age' => 25,
),
array(
'id' => 2,
'name' => '李四',
'age' => 23,
),
array(
'id' => 3,
'name' => '王五',
'age' => 40,
),
array(
'id' => 4,
'name' => '赵六',
'age' => 31,
),
array(
'id' => 5,
'name' => '黄七',
'age' => 20,
),
);
$sort = array(
'direction' => 'SORT_DESC', //排序顺序标志 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);
/*
输出结果：
array (size=5)
0 =>
array (size=3)
'id' => int 5
'name' => string '黄七' (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 '张三' (length=6)
'age' => int 25
3 =>
array (size=3)
'id' => int 4
'name' => string '赵六' (length=6)
'age' => int 31
4 =>
array (size=3)
'id' => int 3
'name' => string '王五' (length=6)
'age' => int 40
*/
<?php
/**
* 二维数组根据某个字段排序
* 功能：按照用户的年龄倒序排序
* @author ruxing.li
*/
header('Content-Type:text/html;Charset=utf-8');
$arrUsers = array(
array(
'id' => 1,
'name' => '张三',
'age' => 25,
),
array(
'id' => 2,
'name' => '李四',
'age' => 23,
),
array(
'id' => 3,
'name' => '王五',
'age' => 40,
),
array(
'id' => 4,
'name' => '赵六',
'age' => 31,
),
array(
'id' => 5,
'name' => '黄七',
'age' => 20,
),
);
$sort = array(
'direction' => 'SORT_DESC', //排序顺序标志 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);
/*
输出结果：
array (size=5)
0 =>
array (size=3)
'id' => int 5
'name' => string '黄七' (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 '张三' (length=6)
'age' => int 25
3 =>
array (size=3)
'id' => int 4
'name' => string '赵六' (length=6)
'age' => int 31
4 =>
array (size=3)
'id' => int 3
'name' => string '王五' (length=6)
'age' => int 40
*/
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