``` /** * 拷貝對象 * */ clone (obj) { const that =this; let result = Array.isArray(obj) ? [] : {}; for (let key in obj) { if (obj.hasOwnProperty(key)) { if (typeof obj[key] === 'object') { result[key] = that.clone(obj[key]); //遞歸復制 } else { result[key] = obj[key]; } } } return result; }, ```