wppaste
WordPress

email_exists( string $email ): int|false

Since
2.1.0
Source
wp-includes/user.php:2094
Determines whether the given email exists.

Description

For more information on this and similar theme functions, check out the https://developer.wordpress.org/themes/basics/conditional-tags/ Conditional Tags article in the Theme Developer Handbook.

Compatibility

WordPress
since 2.1.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$emailstring
The email to check for existence.

Return value

int|false
The user ID on success, false on failure.

Performance profile

How much work a call to email_exists() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Heavy

Reaches the database via get_user_by().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
14–15

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 16.

Plugin surface
1 hook

Third-party callbacks on 'email_exists' run inside this call, and their cost is not bounded by anything here.

Called by
6

6 places in core call this, so the cost is paid more often than your own code shows.

What it touches

  • querycontent queryget_user_by()called directly
  • hookthird-party callbacksapply_filters()called directly

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost email_exists() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always14–15get_user_by(), apply_filters()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 16 instructions, 14–15 executed per call, 1 branch. The work does not change between versions.

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Hooks and filters fired · 1

One hook fires while email_exists() runs, in this order:

  1. apply_filters( email_exists )filterline 2111 (+17 into the body)

    Filters whether the given email exists.

Uses · 2

Used by · 6

Source code

function email_exists( $email ) {	$user = get_user_by( 'email', $email );	if ( $user ) {		$user_id = $user->ID;	} else {		$user_id = false;	} 	/**	 * Filters whether the given email exists.	 *	 * @since 5.6.0	 *	 * @param int|false $user_id The user ID associated with the email,	 *                           or false if the email does not exist.	 * @param string    $email   The email to check for existence.	 */	return apply_filters( 'email_exists', $user_id, $email );}

Changelog

Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

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Generated from the wordpress-develop 6.9.7 tag, from src/wp-includes/user.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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