用于验证选择框的Javascript

Question

<select name="fruits">
   <option value="apple">Apple</option>
   <option value="orange">Orange</option>
   <option value="pears">Pears</option>
</select>

/* fruits stored in the database */
<?php  $items as $each_fruit) {
   $fruit_count++;
   $a[]=$each_fruit->fruit_name;
?>

所选值已存储在数据库中。我不想再允许加入水果......

如何使用javascript检查？

Answer 1

<?php  $items as $each_fruit) {
   $fruit_count++;
   $a[]=$each_fruit->fruit_name;
?>

$ selectedValue - 将用户选择的值分配给此变量

if (!in_array($selectedValue, $a)) {
    // Do your stuff