Wordpress: Get cat ID by slug

function get_cat( $_slug ) {
	
	$_categories = get_terms( 'category',  array( 'hide_empty' => false, 'order' => 'ASC' ) );
	$_result     = array_values( array_filter( $_categories, function($obj){
		
		if (isset($obj->slug)) {
			if( $obj->slug == [needle] ):
				$_term_id = $obj->term_id;
				return true;
			endif;
		}	
	}));
	
	return $_result[0]->term_id;
}