怎么给WordPress登录和注册表单添加placeholder占位符？

具体思路代码如下：

<?php
    /**
	 * https://www.wp-diary.com
     * https://www.wpshequ.com
	 */
    $args = array(
        'echo'           => false,
        'remember'       => true,
        'redirect'       => ( is_ssl() ? 'https://' : 'http://' ) . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'],
        'form_id'        => 'mcl-loginform',
        'id_username'    => 'user_login',
        'id_password'    => 'user_pass',
        'id_remember'    => 'rememberme',
        'id_submit'      => 'wp-submit',
        'label_username' => false,
        'label_password' => false,
        'label_remember' => __( 'Remember Me' ),
        'label_log_in'   => __( 'Log In' ),
        'value_username' => '',
        'value_remember' => false
    );
    $form = wp_login_form($args );
    //add the placeholders
    $form = str_replace('name="log"', 'name="log" placeholder="用户名/邮箱/手机号："', $form);
    $form = str_replace('name="pwd"', 'name="pwd" placeholder="请输入密码："', $form);
    echo $form;
?>

那么按照这个思路，WordPress的注册表单您也可以这样来添加placeholder