Function Reference/email exists

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Description

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.

Usage

%%%<?php

  if( email_exists( $email )) {
     /* stuff to do when mail exists */
  }

?>%%%

Parameter

tt$email/tt
(string) (required) The E-mail address to check
Default: Nonenoinclude

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Notes

This template is for standardizing how parameters look in the Function Reference and in Template Tags. Here is an example of this template being called: prenowiki检查到模板循环:模板:Parameter/nowiki/pre 检查到模板循环:模板:Parameter

The usage of this template is below: prenowiki检查到模板循环:模板:Parameter/nowiki/pre Let's take a closer look at the parameters..

name
The name of the parameter.
datatype
The datatype that should be given for this parameter when called.
  • string
  • integer
  • boolean
  • mixed
description
A short description of the parameter.
importance
Set this parameter to optional if the parameter is optional. Otherwise, do not declare this parameter—it defaults to required.
  • required
  • optional
default
If this parameter is optional, ttdefault/tt is the value that will be used if the parameter is not declared.

wordpress.org.cn /div /noinclude

Return

  • If the E-mail exists, function returns the ID of the user to whom the E-mail is registered.
  • If the E-mail does not exist, function returns false.

Examples

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.

<?php
  $email = 'myemail@example.com';
  if ( email_exists($email) )
    echo "That E-mail is registered to user number " . email_exists($email);
  else
    echo "That E-mail doesn't belong to any registered users on this site";
?>

Notes

Change Log

Since: 2.1.0

Source File

email_exists() is located in onlyincludecodewp-includes/user.php/code/onlyinclude

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Template Description

Link to the source code on http://core.trac.wordpress.org/browser/.

Parameters

  1. filename
  2. (option) path to codetag/code (version) or codetrunk/code. This option is only used for a new function.br /Default: codetrunk/code -- trunk is the latest bleeding edge development version of WordPress.

Usage

Link to the stable version: pre检查到模板循环:模板:Trac/pre

Link to trunk: pre检查到模板循环:模板:Trac/pre

/div

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Related

Conditional Tags: comments_open(), is_local_attachment(), is plugin active(), is_404(), is_admin(), is_archive(), is_attachment(), is_author(), is_category(), is_comments_popup(), is_date(), is_day(), is_feed(), is_front_page(), is_home(), is_month(), is_new_day(), is_page(), is_page_template(), is_paged(), is_plugin_page(), is_preview(), is_search(), is_single(), is_singular(), is_sticky(), is_tag(), is_tax(), is_taxonomy_hierarchical(), is_time(), is_trackback(), is_year(), in_category(), in_the_loop(), is_active_sidebar(), is_active_widget(), is_blog_installed(), is_dynamic_sidebar(), is_user_logged_in(), has_excerpt(), has_post_image(), has_tag(), pings_open(), post_type_exists(), taxonomy_exists(), term_exists(), username exists()

includeonlydiv style=clear:both; background-color:#F7F7F7; border:1px solid #CCCCCC; color:#000000; padding:7px; margin:0.5em auto 0.5em auto; vertical-align:middle;See also index of Function Reference and index of Template Tags./div/includeonlynoinclude

Description

This Template is used by Codex:Template Messages.

Usage

pre 检查到模板循环:模板:Message /pre

Result

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/noinclude