PHP数组排序函数合集 以及之间的联系

Posted by admin on 2012, August 2

**下边提到的几个数组函数的排序有一些共性:

1 数组被作为排序函数的参数,排序以后,数组本身就发生了改变,函数的返回值为bool类型。

2 函数**名中出现a表示**association,含义为,在按值排序的过程中**,保持key=>value的对应关系不变

3 函数名中出现单k表示key,含义为,在按值排序的过程中按照数组key而不是数组的值排序

4 函数名中出现单r的表示reverse,含义为,按照跟不加r的相反的顺序排列

5 函数名中出现单u的表示user-defined,含义为,使用用户自定义函数排序,如果函数的逻辑是参数1<参数2返回负数,则按照升序排列(p1小2返负升)。

**

——————–sort函数升序排序——————————–**

bool sort ( array &$array [, int $sort_flags= SORT_REGULAR ] )

结果:

array

0 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>
  1 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  2 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
  3 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)</em>
<strong>--------------------rsort降序排列--------------------</strong>
<?php
$fruits = array("lemon", "orange", "banana", "apple");
rsort($fruits);
var_dump($fruits);
?>
结果:
<strong>array</strong>
  0 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)</em>
  1 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
  2 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  3 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>
<strong>---------------asort按照二维数组值的升序排列(保持key=>value的关联关系)-----------</strong>
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
asort($fruits);
var_dump($fruits);
?>
结果:
<strong>array</strong>
  'c' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>
  'b' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  'd' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
  'a' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)</em>
<strong>--------------arsort按照二维数组值的降序排列(保持key=>value的关联关系)</strong>--------------
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
arsort($fruits);
var_dump($fruits);
?>
结果
<strong>array</strong>
  'a' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)</em>
  'd' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
  'b' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  'c' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>

--------------------<span class="type"><strong>ksort按照数组的key升序排列</strong>--------------</span> <?php

`$fruits = array(“d”=>”lemon”, “a”=>”orange”, “b”=>”banana”, “c”=>”apple”);

ksort($fruits);

var_dump($fruits);

?>

结果

`array

'a' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)</em>
  'b' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  'c' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>
  'd' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
<strong>---------------------krsort按照数组key的降序排列--------------------------------</strong>
<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
krsort($fruits);
var_dump($fruits);
?>

<strong>array</strong>
  'd' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'lemon'</span> <em>(length=5)</em>
  'c' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'apple'</span> <em>(length=5)</em>
  'b' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'banana'</span> <em>(length=6)</em>
  'a' <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'orange'</span> <em>(length=6)


</em><strong>----------------<span class="methodname">usort</span>函数按照用户自定义的函数排序----------------
</strong><?php
function cmp($a, $b)
{
    if ($a == $b) {
        return 0;
    }
    return ($a < $b) ? -1 : 1;
}

$a = array(3, 2, 5, 6, 1);

usort($a, "cmp");

var_dump($a);
?><strong>
结果:
array</strong>
  0 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">1</span>
  1 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">2</span>
  2 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">3</span>
  3 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">5</span>
  4 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">6</span>
<strong>-----------------</strong><span class="methodname"><strong>uksort</strong></span><strong>使用自定义函数按照数组的key排序-----------------
</strong><?php
function cmp($a, $b)
{
    $a = preg_replace('@^(a|an|the) @', '', $a);
    $b = preg_replace('@^(a|an|the) @', '', $b);
    return strcasecmp($a, $b);
}

$a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4);

uksort($a, "cmp");

var_dump($a);
?>
结果:
<strong>array</strong>
  'an apple' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">3</span>
  'a banana' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">4</span>
  'the Earth' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">2</span>
  'John' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">1</span>
<strong>-------------------uasort将数组用自定义函数按照value排序,保持索引关系不变---------
</strong><?php
// Comparison function
function cmp($a, $b) {
    if ($a == $b) {
        return 0;
    }
    return ($a < $b) ? -1 : 1;
}

// Array to be sorted
$array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4);
var_dump($array);

// Sort and print the resulting array
uasort($array, 'cmp');
var_dump($array);
?>
<strong>结果:
array</strong>
  'a' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">4</span>
  'b' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">8</span>
  'c' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-1</span>
  'd' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-9</span>
  'e' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">2</span>
  'f' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">5</span>
  'g' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">3</span>
  'h' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-4</span>
<strong>array</strong>
  'd' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-9</span>
  'h' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-4</span>
  'c' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">-1</span>
  'e' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">2</span>
  'g' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">3</span>
  'a' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">4</span>
  'f' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">5</span>
  'b' <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">8</span>
<strong>-------------------</strong><span class="methodname"><strong>array_multisort排序多个数组或多维数组</strong></span><strong>---------</strong>
<?php
$ar = array(
       array("10", 11, 100, 100, "a"),
       array(   1,  2, "2",   3,   1)
      );
   
array_multisort($ar[0], SORT_ASC, SORT_STRING,
                $ar[1], SORT_NUMERIC, SORT_DESC);
var_dump($ar);
?>
结果:
<strong>array</strong>
  0 <span style="color:#888a85">=></span>
<strong>array</strong>
      0 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'10'</span> <em>(length=2)</em>
      1 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">100</span>
      2 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">100</span>
      3 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">11</span>
      4 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'a'</span> <em>(length=1)</em>
  1 <span style="color:#888a85">=></span>
<strong>array</strong>
      0 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">1</span>
      1 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">3</span>
      2 <span style="color:#888a85">=></span> 

string

 <span style="color:#cc0000">'2'</span> <em>(length=1)</em>
      3 <span style="color:#888a85">=></span> 

int

 <span style="color:#4e9a06">2</span>
      4 <span style="color:#888a85">=></span> 

int

<span style="color:#4e9a06">1</span>
//说明:
1 上例中:$ar数组优先按照$ar[0]的字符串值升序排列,如果字符串值相等,再按照$ar[1]数组的数字值降序排列。
2 array_multisort函数的任意一个位置的参数如果是数组,表示排序时用的值,
如果有多个数组参数,优先按照前边的数组值进行排序,如果是常量,例如<strong><tt class="constant">
SORT_ASC</tt></strong>,<strong><tt class="constant"> SORT_DESC</tt></strong>, <strong><tt class="constant">SORT_REGULAR</tt></strong>,<strong><tt class="constant">SORT_NUMERIC</tt></strong>,<strong><tt class="constant"> SORT_STRING</tt></strong>.
表示排序方法(数组取值前优先)。










==========================================================================================

PHP二维数组排序函数

PHP一维数组的排序可以用sort(),asort(),arsort()等函数,但是PHP二维数组的排序需要自定义。

以下函数是对一个给定的二维数组按照指定的键值进行排序,先看函数定义:

view sourceprint?

01.function array_sort($arr,$keys,$type='asc'){

02.$keysvalue = $new_array ` = array();`

03.foreach ($arr ` as $k=>$v``){`

04.$keysvalue[$k] = $v[$keys];

05.}

06.if($type == 'asc'){

07.asort($keysvalue);

08.}else{

09.arsort($keysvalue);

10.}

11.reset($keysvalue);

12.foreach ($keysvalue ` as $k=>$v``){`

13.$new_array[$k] = $arr[$k];

14.}

15.return $new_array;

16.}

它可以对二维数组按照指定的键值进行排序,也可以指定升序或降序排序法(默认为升序),用法示例:

view sourceprint?

01.$array = array(

02.array('name'=>'手机','brand'=>'诺基亚','price'=>1050),

03.array('name'=>'笔记本电脑','brand'=>'lenovo','price'=>4300),

04.array('name'=>'剃须刀','brand'=>'飞利浦','price'=>3100),

05.array('name'=>'跑步机','brand'=>'三和松石','price'=>4900),

06.array('name'=>'手表','brand'=>'卡西欧','price'=>960),

07.array('name'=>'液晶电视','brand'=>'索尼','price'=>6299),

08.array('name'=>'激光打印机','brand'=>'惠普','price'=>1200)

09.);

10.

11.$ShoppingList = array_sort($array,'price');

12.print_r($ShoppingList);

上面是对$array这个二维数组按照’price’从低到高的排序。

输出结果:(略)。