wp-includes/load.php:1773Checks whether the given variable is a WordPress Error.
$thingmixedboolOne hook fires while is_wp_error() runs, in this order:
Fires when `is_wp_error()` is called and its parameter is an instance of `WP_Error`.
function is_wp_error( $thing ) { $is_wp_error = ( $thing instanceof WP_Error ); if ( $is_wp_error ) { /** * Fires when `is_wp_error()` is called and its parameter is an instance of `WP_Error`. * * @since 5.6.0 * * @param WP_Error $thing The error object passed to `is_wp_error()`. */ do_action( 'is_wp_error_instance', $thing ); } return $is_wp_error;}Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/load.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.