username_exists

The timeline below displays how wordpress function username_exists has changed across different WordPress versions. If a version is not listed, refer to the next available version below.

WordPress Version: 5.6

/**
 * Determines whether the given username exists.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.0.0
 *
 * @param string $username The username to check for existence.
 * @return int|false The user ID on success, false on failure.
 */
function username_exists($username)
{
    $user = get_user_by('login', $username);
    if ($user) {
        $user_id = $user->ID;
    } else {
        $user_id = false;
    }
    /**
     * Filters whether the given username exists.
     *
     * @since 4.9.0
     *
     * @param int|false $user_id  The user ID associated with the username,
     *                            or false if the username does not exist.
     * @param string    $username The username to check for existence.
     */
    return apply_filters('username_exists', $user_id, $username);
}

WordPress Version: 5.1

/**
 * Determines whether the given username exists.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.0.0
 *
 * @param string $username Username.
 * @return int|false The user's ID on success, and false on failure.
 */
function username_exists($username)
{
    $user = get_user_by('login', $username);
    if ($user) {
        $user_id = $user->ID;
    } else {
        $user_id = false;
    }
    /**
     * Filters whether the given username exists or not.
     *
     * @since 4.9.0
     *
     * @param int|false $user_id  The user's ID on success, and false on failure.
     * @param string    $username Username to check.
     */
    return apply_filters('username_exists', $user_id, $username);
}

WordPress Version: 5.0

/**
 * Determines whether the given username exists.
 * 
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/ 
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.0.0
 *
 * @param string $username Username.
 * @return int|false The user's ID on success, and false on failure.
 */
function username_exists($username)
{
    if ($user = get_user_by('login', $username)) {
        $user_id = $user->ID;
    } else {
        $user_id = false;
    }
    /**
     * Filters whether the given username exists or not.
     *
     * @since 4.9.0
     *
     * @param int|false $user_id  The user's ID on success, and false on failure.
     * @param string    $username Username to check.
     */
    return apply_filters('username_exists', $user_id, $username);
}

WordPress Version: 4.9

/**
 * Checks whether the given username exists.
 *
 * @since 2.0.0
 *
 * @param string $username Username.
 * @return int|false The user's ID on success, and false on failure.
 */
function username_exists($username)
{
    if ($user = get_user_by('login', $username)) {
        $user_id = $user->ID;
    } else {
        $user_id = false;
    }
    /**
     * Filters whether the given username exists or not.
     *
     * @since 4.9.0
     *
     * @param int|false $user_id  The user's ID on success, and false on failure.
     * @param string    $username Username to check.
     */
    return apply_filters('username_exists', $user_id, $username);
}

WordPress Version: 4.3

/**
 * Checks whether the given username exists.
 *
 * @since 2.0.0
 *
 * @param string $username Username.
 * @return int|false The user's ID on success, and false on failure.
 */
function username_exists($username)
{
    if ($user = get_user_by('login', $username)) {
        return $user->ID;
    }
    return false;
}

WordPress Version: 3.7

/**
 * Checks whether the given username exists.
 *
 * @since 2.0.0
 *
 * @param string $username Username.
 * @return null|int The user's ID on success, and null on failure.
 */
function username_exists($username)
{
    if ($user = get_user_by('login', $username)) {
        return $user->ID;
    } else {
        return null;
    }
}