判断邮箱地址是否已经被注册过

描述

译文

该函数判断所给电子邮件地址（$email）是否已被某一用户名注册，并返回用户编号（邮件地址不存在则返回false）。参见username_exists.

原文

This function will check whether or not a given email address ($email) has already been registered to a username, and returns that users ID (or false if none exists). See also username_exists.

This function is normally used when a user is registering, to ensure that the E-mail address the user is attempting to register with has not already been registered.

用法

<?php
   if( email_exists( $email )) {
      /* stuff to do when email address exists */
   }
?>

示例

If the E-mail exists, echo the ID number to which the E-mail is registered. Otherwise, tell the viewer that it does not exist.

历史

添加于 版本: 2.1.0

源文件

email_exists() 函数的代码位于 wp-includes/user.php

相关

• Article(文章): Introduction to WordPress conditional functions
• Function(函数): comments_open()
• Function(函数): is_404()
• Function(函数): is_admin()
• Function(函数): is_admin_bar_showing()
• Function(函数): is_archive()
• Function(函数): is_attachment()
• Function(函数): is_author()
• Function(函数): is_category()
• Function(函数): is_comments_popup()
• Function(函数): is_date()
• Function(函数): is_day()
• Function(函数): is_feed()
• Function(函数): is_front_page()
• Function(函数): is_home()
• Function(函数): is_local_attachment()
• Function(函数): is_main_query
• Function(函数): is_multi_author
• Function(函数): is_month()
• Function(函数): is_new_day()
• Function(函数): is_page()
• Function(函数): is_page_template()
• Function(函数): is_paged()
• Function(函数): is_plugin_active()
• Function(函数): is_plugin_active_for_network()
• Function(函数): is_plugin_inactive()
• Function(函数): is_plugin_page()
• Function(函数): is_post_type_archive()
• Function(函数): is_preview()
• Function(函数): is_search()
• Function(函数): is_single()
• Function(函数): is_singular()
• Function(函数): is_sticky()
• Function(函数): is_tag()
• Function(函数): is_tax()
• Function(函数): is_taxonomy_hierarchical()
• Function(函数): is_time()
• Function(函数): is_trackback()
• Function(函数): is_year()
• Function(函数): in_category()
• Function(函数): in_the_loop()
• Function(函数): is_active_sidebar()
• Function(函数): is_active_widget()
• Function(函数): is_blog_installed()
• Function(函数): is_rtl()
• Function(函数): is_dynamic_sidebar()
• Function(函数): is_user_logged_in()
• Function(函数): has_excerpt()
• Function(函数): has_post_thumbnail()
• Function(函数): has_tag()
• Function(函数): pings_open()
• Function(函数): email exists()
• Function(函数): post_type_exists()
• Function(函数): taxonomy_exists()
• Function(函数): term_exists()
• Function(函数): username exists()
• Function(函数): wp_attachment_is_image()
• Function(函数): wp_script_is()

• 原文：http://codex.wordpress.org/Function_Reference/email_exists