Wordpress get user id by login name

Ho开发者_运维知识库w do i get the user id from user login name in wordpress?

get_userdatabylogin is now deprecated, it is possible to get the same result via

get_user_by

example :

$user = get_user_by('login','loginname');
if($user)
{
   echo $user->ID;
}

link to the ticket about this change

By using get_userdatabylogin:

$user = get_userdatabylogin('loginname');
if($user){
   echo $user->ID;
}

Example:

$user = get_userdatabylogin('admin');
if($user) echo $user->ID; // Outputs 1

UPDATE: the function get_userdatabylogin has been deprecated, and replaced with get_user_by(). Refer to Dalen's solution to this question.

You also can use get_current_user_id()

<?php
    $user_id = get_current_user_id();
    echo "ID User : ".$user_id ;
    if ($user_id == 0) {
        echo 'You are currently not logged in.';
    } else {
        echo 'You are logged in as user '.$user_id;
    }
?>