PHP 有一些用来排序数组的函数, 这个文档会把它们列出来。
主要区别有:
$array['key'] = 'value';。
| 函数名称 | 排序依据 | 数组索引键保持 | 排序的顺序 | 相关函数 |
|---|---|---|---|---|
| array_multisort() | 值 | string 键保持不变,int 键重新索引 | 第一个数组或者由选项指定 | array_walk() |
| asort() | 值 | 是 | 升序 | arsort() |
| arsort() | 值 | 是 | 降序 | asort() |
| krsort() | 键 | 是 | 降序 | ksort() |
| ksort() | 键 | 是 | 升序 | krsort() |
| natcasesort() | 值 | 是 | 自然排序,大小写不敏感 | natsort() |
| natsort() | 值 | 是 | 自然排序 | natcasesort() |
| rsort() | 值 | 否 | 降序 | sort() |
| shuffle() | 值 | 否 | 随机 | array_rand() |
| sort() | 值 | 否 | 升序 | rsort() |
| uasort() | 值 | 是 | 由用户定义 | uksort() |
| uksort() | 键 | 是 | 由用户定义 | uasort() |
| usort() | 值 | 否 | 由用户定义 | uasort() |
While this may seem obvious, user-defined array sorting functions ( uksort(), uasort(), usort() ) will *not* be called if the array does not have *at least two values in it*.
The following code:
<?php
function usortTest($a, $b) {
var_dump($a);
var_dump($b);
return -1;
}
$test = array('val1');
usort($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.Another way to do a case case-insensitive sort by key would simply be:
<?php
uksort($array, 'strcasecmp');
?>
Since strcasecmp is already predefined in php it saves you the trouble to actually write the comparison function yourself.