wordpress login user programmatically

Use the following code to programmatically login a user in WordPress:

// Get the user information based on the username
$user = get_user_by( 'login', 'username' );

// Log in the user
wp_set_current_user( $user->ID, $user->user_login );
wp_set_auth_cookie( $user->ID );
do_action( 'wp_login', $user->user_login );

Explanation: 1. The get_user_by() function retrieves the user based on the username provided. 2. wp_set_current_user() sets the current user by ID and username. 3. wp_set_auth_cookie() sets the authentication cookies for the logged-in user. 4. The do_action( 'wp_login', $user->user_login ) action triggers the login action for WordPress.