Php 使用uksort（）对数组进行排序

我有一个这样的数组：

$a = array("MA1" => 0, "MA10" => 1, "MA20" => 2, "MA5" => 3, "SM10" => 4, "SM8" => 5, "SM20" => 6, "SN33" => 7);

我想对其进行排序，我将按照以下顺序进行排序：

$a = array("MA1" => 0, "MA5" => 3, "MA10" => 1, "MA20" => 2, "SM8" => 5, "SM10" => 4, "SM20" => 6, "SN33" => 7);

所以我需要一个顺序，在前两个字符内按字母顺序，其余字符按数字顺序。所以我想我必须和你一起做这件事

uksort($a, "cmp");

所以我需要这样一个函数：

function cmp($a, $b) {
    // ???
    return strcasecmp($a, $b);
}

我需要如何编写函数才能使顺序正确

---

提前向您表示感谢和问候。

您可以使用内置的自然比较功能：

$a = array("MA1" => 0, "MA10" => 1, "MA20" => 2, "MA5" => 3, "SM10" => 4, "SM8" => 5, "SM20" => 6, "SN33" => 7);
uksort($a, "strnatcasecmp");
print_r($a);

上述代码将产生以下输出：

Array
(
    [MA1] => 0
    [MA5] => 3
    [MA10] => 1
    [MA20] => 2
    [SM8] => 5
    [SM10] => 4
    [SM20] => 6
    [SN33] => 7
)

---

您可以使用内置的自然比较功能：

$a = array("MA1" => 0, "MA10" => 1, "MA20" => 2, "MA5" => 3, "SM10" => 4, "SM8" => 5, "SM20" => 6, "SN33" => 7);
uksort($a, "strnatcasecmp");
print_r($a);

上述代码将产生以下输出：

Array
(
    [MA1] => 0
    [MA5] => 3
    [MA10] => 1
    [MA20] => 2
    [SM8] => 5
    [SM10] => 4
    [SM20] => 6
    [SN33] => 7
)