[Javascript] 객체 내부의 key값 체크

 

key in object

const obj = {
  name: "Jay",
  age: 29,
};

console.log("name" in obj); // true
console.log("age" in obj); // true
console.log("gender" in obj); // false

 

 

Object.hasOwnProperty

 

const obj = {
  name: "Jay",
  age: 29,
};

console.log(obj.hasOwnProperty("name")); // ture
console.log(obj.hasOwnProperty("age")); // ture
console.log(obj.hasOwnProperty("gender")); // false