PHP：我需要嵌套的 foreach 循环还是多个数组？

Question

我不确定描述我需要做什么的术语。两个嵌套的 foreach 循环？多个数组？多维数组？

我正在计算每个状态（AK、AL、AR 等）出现的总次数

$states_count[] = $state;
$count_by_state = array_count_values($states_count);

var_dump($count_by_state) 给了我

["AK"]=> int(3) ["AL"]=> int(6) ["AR"]=> int(4) ["AZ"]=> int(9) ["CA"]=> int(98) ["CO"]=> int(44) ....

所以阿拉斯加总数是 3，阿拉巴马州总数是 6，依此类推

在单独的代码中，我使用这个 foreach 来构建一个菜单：

<?php $states = array('AK'=>'Alaska', 'AL'=>'Alabama'....  );

foreach ($states as $key => $value) {
echo $key; echo $value; echo ',';
}

输出 AK 阿拉斯加、AL 阿拉巴马州、AR 阿肯色州...

但是我该如何让它发挥作用呢？

foreach ($states as $key => $value) {
echo $key; echo $value; echo $each-individual-state-count-total from $count_by_state)

Answer 1

您可以使用 foreach 循环的键索引到 $count_by_state 数组（并可能先检查键是否存在）

$count_by_state = [
    "AK" => 3,
    "AL" => 6,
    "XXX" => 9
];
$states = array('AK' => 'Alaska', 'AL' => 'Alabama');

foreach ($states as $key => $value) {
    if (array_key_exists($key, $count_by_state)) {
        echo $value . "," . $count_by_state[$key] . PHP_EOL;
    }
}

输出

Alaska,3
Alabama,6

PHP：我需要嵌套的 foreach 循环还是多个数组？

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