natsort — 用“自然排序”算法对数组排序

2017-12-18 16:21:32
linefo
475
最后编辑:linefo 于 2017-12-18 16:22:58

natsort

(PHP 4, PHP 5, PHP 7)

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($array1);
echo 
"Standard sorting\n";
print_r($array1);

natsort($array2);
echo 
"\nNatural order sorting\n";
print_r($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 numbers\n";
$negative = array('-5','3','-2','0','-1000','9','1');
print_r($negative);
natsort($negative);
print_r($negative);

echo 
"Zero padding\n";
$zeros = array('09''8''10''009''011''0'); 
print_r($zeros);
natsort($zeros);
print_r($zeros);

echo 
"Other characters interfering\n";
$images_oops = array('image_1.jpg','image_12.jpg''image_21.jpg''image_4.jpg');
print_r($images_oops);
natsort($images_oops);
print_r($images_oops);

echo 
"Sort by keys\n";
$smoothie = array('orange' => 1'apple' => 1'yogurt' => 4'banana' => 4);
print_r($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