=== undefined ? {} : options; var size = options.size === undefined ? 'big' : options.size; var cords = options.cords === undefined ? { x: 0, y: 0 } : options.cords; var radius = options.radius === undefined ? 25 : options.radius; console.log(size, cords, radius); // now finally do some chart drawing } drawES5Chart({ cords: { x: 18, y: 30 }, radius: 30 });