wp-includes/class-wp-query.php:4185Determines whether the query is for an existing post type archive page.
$post_typesstring|string[]optional''bool public function is_post_type_archive( $post_types = '' ) { if ( empty( $post_types ) || ! $this->is_post_type_archive ) { return (bool) $this->is_post_type_archive; } $post_type = $this->get( 'post_type' ); if ( is_array( $post_type ) ) { $post_type = reset( $post_type ); } $post_type_object = get_post_type_object( $post_type ); if ( ! $post_type_object ) { return false; } return in_array( $post_type_object->name, (array) $post_types, true ); }Introduced in 3.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-query.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.