如何在PHP中找到数组中的字符串？

$array = array("apple", "orange", "banana");
$string = "orange";

if (in_array($string, $array)) {
    echo "字符串在数组中";
} else {
    echo "字符串不在数组中";
}

$array = array("apple", "orange", "banana");
$string = "orange";

$key = array_search($string, $array);

if ($key !== false) {
    echo "字符串在数组中，键名为：" . $key;
} else {
    echo "字符串不在数组中";
}

$array = array("apple", "orange", "banana");
$string = "orange";

foreach ($array as $key => $value) {
    if ($value === $string) {
        echo "字符串在数组中，键名为：" . $key;
        break;
    }
}