如何忽略区分大小写并计算数组值？

Question

无论大小写敏感，计算数组值的最简单方法是什么？

试图

$arr=array("A","B","b","A","b", "a", "A");

print_r(array_count_values($arr));

或者：

$arr=array("AliCE","Alice","bob","AlICE","BOB", "aLIce", "alice");

print_r(array_count_values($arr));

演示

电流输出

Array

(

    [A] => 3

    [B] => 1

    [b] => 2

    [a] => 1

)

期望输出

Array

(

    [A] => 4

    [B] => 2

)

或者：

Array

(

    [a] => 4

    [b] => 2

)

Answer 1

我会使用array_map但作为替代，加入一个字符串，更改大小写，拆分为一个数组：print_r(array_count_values(str_split(strtolower(implode($arr)))));

Answer 2

您可以先使用strtoupper以下方法将字母映射为大写：$arr = array("A","B","b","A","b", "a", "A");print_r(array_count_values(array_map('strtoupper', $arr)));输出：(    [A] => 4    [B] => 3)

Answer 3

您可以使用foreach与array_key_exists和strtoupper$arr=array("A","B","b","A","b", "a", "A");$res = [];foreach($arr as $k => $v){    array_key_exists(strtoupper($v), $res) ? ($res[strtoupper($v)]++) : ($res[strtoupper($v)] = 1); }print_r($res);