natsort
(PHP 4, PHP 5)
natsort —
用“自然排序”算法对数组排序
说明
bool natsort ( array &$array )
本函数实现了一个和人们通常对字母数字字符串进行排序的方法一样的排序算法并保持原有键／值的关联，这被称为“自然排序”。本算法和通常的计算机字符串排序算法（用于
sort()）的区别见下面示例。
参数
array
输入的 array。
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE。
更新日志
版本
说明
5.2.10
Zero padded numeric strings (e.g., ‘00005’) now essentially ignore the 0 padding.
范例
Example #1 natsort() examples demonstrating basic usage
<?php
$array1 = $array2 = array("img12.png", "img10.png", "img2.png", "img1.png");
asort($array1);
echo "Standard sortingn";
print_r($array1);
natsort($array2);
echo "nNatural order sortingn";
print_r($array2);
?>
以上例程会输出：
Standard sorting
Array
(
[3] => img1.png
[1] => img10.png
[0] => img12.png
[2] => img2.png
)
Natural order sorting
Array
(
[3] => img1.png
[2] => img2.png
[1] => img10.png
[0] => img12.png
)
For more information see: Martin Pool’s » Natural Order String Comparison
page.
Example #2 natsort() examples demonstrating potential gotchas
<?php
echo "Negative numbersn";
$negative = array('-5','3','-2','0','-1000','9','1');
print_r($negative);
natsort($negative);
print_r($negative);
echo "Zero paddingn";
$zeros = array('09', '8', '10', '009', '011', '0');
print_r($zeros);
natsort($zeros);
print_r($zeros);
echo "Other characters interferingn";
$images_oops = array('image_1.jpg','image_12.jpg', 'image_21.jpg', 'image_4.jpg');
print_r($images_oops);
natsort($images_oops);
print_r($images_oops);
echo "Sort by keysn";
$smoothie = array('orange' => 1, 'apple' => 1, 'yogurt' => 4, 'banana' => 4);
print_r($smoothie);
uksort( $smoothie, 'strnatcmp');
print_r($smoothie);
?>
以上例程会输出：
Negative numbers
Array
(
[0] => -5
[1] => 3
[2] => -2
[3] => 0
[4] => -1000
[5] => 9
[6] => 1
)
Array
(
[2] => -2
[0] => -5
[4] => -1000
[3] => 0
[6] => 1
[1] => 3
[5] => 9
)
Zero padding
Array
(
[0] => 09
[1] => 8
[2] => 10
[3] => 009
[4] => 011
[5] => 0
)
Array
(
[5] => 0
[1] => 8
[3] => 009
[0] => 09
[2] => 10
[4] => 011
)
Other characters interfering
Array
(
[0] => image_1.jpg
[1] => image_12.jpg
[2] => image_21.jpg
[3] => image_4.jpg
)
Array
(
[0] => image_1.jpg
[3] => image_4.jpg
[1] => image_12.jpg
[2] => image_21.jpg
)
Sort by keys
Array
(
[orange] => 1
[apple] => 1
[yogurt] => 4
[banana] => 4
)
Array
(
[apple] => 1
[banana] => 4
[orange] => 1
[yogurt] => 4
)
参见
natcasesort() – 用“自然排序”算法对数组进行不区分大小写字母的排序
数组排序函数对比
strnatcmp() – 使用自然排序算法比较字符串
strnatcasecmp() – 使用“自然顺序”算法比较字符串（不区分大小写）
