從數組中獲取鍵或值以在php中使用

Question

我想將值從數組分配給一個簡單的變量，我的代碼如下：

$codeval = $_POST['code']; //can be Apple or Banana or Cat or Dog
$systemrefcode = array("a" => "Apple", "b" => "Banana", "C" => "Cat", "D" => "Dog");

foreach($systemrefcode as $code => $value) {
     if($codeval == $value){ //if Apple exists in array then assign code and use it further
        $codes = $code;//Assign code to codes to use in next step

     }
$selection = 'Your Selection is -'.$codes.'and its good.';
echo $selection;

當我在控制台中簽入時，它沒有顯示任何響應。 我究竟做錯了什么？

Answer 1

您可以使用array_search（）獲得所需值的鍵：

$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

$key = array_search('green', $array); // $key = 2;

因此，對於您的代碼，您可以像這樣使用：

$codeval = $_POST['code'];
$systemrefcode = array("a" => "Apple", "b" => "Banana", "C" => "Cat", "D" => "Dog");

$code = array_search($codeval, $systemrefcode);

$selection = 'Your Selection is - '.$code.' and its good.';
echo $selection;

OBS：

1. 如果找不到值， array_search（）將返回false ；否則，返回false 。
2. array_search（） 區分大小寫 ，因此如果數組中有“ Apple ”並搜索“ apple ”，則它將返回false 。

Answer 2

您可以在有匹配項時break foreach ，然后回顯字符串。

$post = "1-Apple";
$codeval = explode('-', $post)[1];
$systemrefcode = array("a" => "Apple", "b" => "Banana", "C" => "Cat", "D" => "Dog");
$codes = "";

foreach ($systemrefcode as $code => $value) {
    if ($codeval === $value) { //if Apple exists in array then assign code and use it further
        $codes = $code;//Assign code to codes to use in next step
        break;
    }
}

if ($codes !== "") {
    $selection = 'Your Selection is -' . $codes . ' and its good.';
    echo $selection; // Your Selection is -a and its good.
} else {
    echo "codes is empty";
}

Answer 3

您可以翻轉$systemrefcode數組，使值成為鍵，反之亦然。

$coderefsystem = array_flip($systemrefcode);
$codes = $coderefsystem($codeval);
$selection = 'Your Selection is -'.$codes.'and its good.';
echo $selection;