1. Property value shorthand / Constructor function // 3. Property value shorthand const person1 = {name : 'aa', age : 2}; const person2 = new Person('bb',11); console.log(person1); // {name: "aa", age: 2} console.log(person2); // Person {name: "bb", age: 11} // 4. Constructor function function Person(name, age) { this.name = name; this.age = age; } 2. key 값이 있는지 체크 (in operator: property existen..