PHP:如何按字母顺序对数组的值进行排序？

Question

我想在PHP中按字母顺序对数组的值进行排序.如果所有值都以相同的字符开头,那么它们应该使用第二个字符进行排序,依此类推.忽略区分大小写.

例如:

before:
values[0] = "programming";
values[1] = "Stackoverflow";
values[2] = "question";
values[3] = "answers";
values[4] = "AA Systems";

after:
values[0] = "AA Systems";
values[1] = "answers";
values[2] = "programming";
values[3] = "question";
values[4] = "Stackoverflow";

我找到了一些算法,但我想要一种快速且语句数量少的方法.忽略区分大小写对我来说很特别.谢谢.

Answer 1

看到

• natcasesort:http://www.php.net/manual/en/function.natcasesort.php
• usort:http://www.php.net/manual/en/function.usort.php,带有比较strtolower(a)和比较的比较器功能strtolower(b).

Answer 2

您的示例有两个假设:

1. 你只处理简单的一维数组.

2. 按字母顺序排序后,您的索引将更新,以便按字母顺序将第一个元素分配给键0,依此类推.

给定这些参数,最简单的解决方案是使用数组方法sort().用你的例子:

$values[0] = "programming";
$values[1] = "Stackoverflow";
$values[2] = "question";
$values[3] = "answers";
$values[4] = "AA Systems";

sort($values);

这将导致以下结果:

Array {
     [0] => AA Systems
     [1] => Stackoverflow
     [2] => answers
     [3] => programming
     [4] => question
}

There are other array sorting functions that might be a better fit. For instance, the simple one I use above puts upper-case in front of lower-case, so if you had "security" as an item (all lower-case) it would go after "Stackoverflow" since the upper-case s would take precedence over se vs. st. To sort without case-sensitivity, you could use natcasesort(), which would produce the following with the given array:

Array {
     [0] => AA Systems
     [1] => answers
     [2] => programming
     [3] => question
     [4] => Stackoverflow
}