如何删除 WP_User_Query 中重复的元值

Question

我创建了一个名为“designation”的自定义用户元字段，并在循环中获取其所有元值，但它显示了 duplicates 值。我在循环之前和循环内部尝试过 array_unique() 函数，但不起作用。请指导我如何删除重复项。

<form action="" method="post">
    <select name="designation" onchange="if(this.value != 0) && if(this.value != 1){ this.form.submit(); }">
        <option value="1">Select Category</option>
        <?php
        $args = array(
            'role' => 'subscriber',
            'meta_key' => 'user_designation'
        );

        $design = array_unique($args);      
        var_dump($design);

        // The Query
        $user_query = new WP_User_Query($design);


        // User Loop
        if ( !empty($user_query->results) ) {
            foreach ( $user_query->results as $user ) {


         ?>
                <option value="<?php  echo get_user_meta($user->ID, 'user_designation', true); ?>"
                    <?php if (isset($_POST['designation']) && $_POST['designation'] == "echo get_user_meta($user->ID, 'user_designation', true);") {echo "selected";} ?> >
                    <?php echo get_user_meta($user->ID, 'user_designation', true); ?>
                </option>
        <?php
            }
        } else {
        ?>
            <option value="0">No Category Found</option>
        <?php
                        }
                        ?>


                        </select>
                        </form>

Answer 1

将用户元存储在变量中并检查变量是否为空，如下面的链接所示-

https://wordpress.stackexchange.com/questions/243867/how-to-get-user-meta-value-in-wordpress/243872?noredirect=1#comment363884_243872