PHP 7.1.0 Alpha 2 Released


PHP 有一些用来排序数组的函数, 这个文档会把它们列出来。


  • 有些函数基于 array 的键来排序, 而其他的基于值来排序的:$array['key'] = 'value';
  • 排序之后键和值之间的关联关系是否能够保持, 是指排序之后数组的键可能 会被重置为数字型的(0,1,2 ...)。
  • 排序的顺序有:字母表顺序, 由低到高(升序), 由高到低(降序),数字排序,自然排序,随机顺序或者用户自定义排序。
  • 注意:下列的所有排序函数都是直接作用于数组本身, 而不是返回一个新的有序的数组。
  • 以下函数对于数组中相等的元素,它们在排序后的顺序是未定义的。 (也即相等元素之间的顺序是不稳定的)。

函数名称 排序依据 数组索引键保持 排序的顺序 相关函数
array_multisort() 键值关联的保持,数字类型的不保持 第一个数组或者由选项指定 array_walk()
asort() 由低到高 arsort()
arsort() 由高到低 asort()
krsort() 由高到低 ksort()
ksort() 由低到高 asort()
natcasesort() 自然排序,大小写不敏感 natsort()
natsort() 自然排序 natcasesort()
rsort() 由高到低 sort()
shuffle() 随机 array_rand()
sort() 由高到低 rsort()
uasort() 由用户定义 uksort()
uksort() 由用户定义 uasort()
usort() 由用户定义 uasort()

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User Contributed Notes 5 notes

"Matthew Rice"
3 years ago
While this may seem obvious, user-defined array sorting functions ( uksort(), uasort(), usort() ) will *not* be called if the array does not have *at least two values in it*.

The following code:                       


function usortTest($a, $b) {
    return -

$test = array('val1');
usort($test, "usortTest");

$test2 = array('val2', 'val3');
usort($test2, "usortTest");


Will output:

string(4) "val3"
string(4) "val2"

The first array doesn't get sent to the function.

Please, under no circumstance, place any logic that modifies values, or applies non-sorting business logic in these functions as they will not always be executed.
oculiz at gmail dot com
5 years ago
Another way to do a case case-insensitive sort by key would simply be:

($array, 'strcasecmp');

Since strcasecmp is already predefined in php it saves you the trouble to actually write the comparison function yourself.
monicse09ku at yahoo dot com
1 year ago
// takes an array and desired key value and returns an array
// searches through an array for a given key, if found the key that row is made the first row and the other rows are inserted accordingly.
// the facility of this function is to get the value with a specific key of an array as the first value.

/////////////////////////////// function starts //////////////////////////////

function dksort($array, $case){
        $a[$case] = $array[$case];
        foreach($array as $key=>$val){

                $a[$key] = $array[$key];

    return $a;

$d = array(

$c = dksort($d, '55');

////////////////////////// function ends ////////////////////////////////////////
1 year ago
simple example sorting dotted version numbers

     function sortByVersionnumber($a,$b){
         $ta=explode(".",$a); $tb=explode(".",$b);
         foreach ($ta as $k => $v){
             if (isset($tb[$k])){
                 if($ta[$k] > $tb[$k]) {
                     return 1;
                 } elseif($ta[$k] < $tb[$k]) {
                     return -1;
         return 0;
     function vnksort(&$array){
         uksort($array ,"sortByVersionnumber");
6 years ago
If you need to perform any of these sort functions on an array containing two or more equivalent values, you can get the equivalents to fall next to each other within the overall ordering (similar to how MySQL's ORDER BY works...) instead of breaking the sort() function, by using ksort() as a second parameter to arbitrarily distinguish any equivalent values by their unique keys:


($array, ksort($array));


Seems like this effect should be built in.  At least the workaround is so short...
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