let name = 'fdongfdong';
let age = 17;
let person = {
name: name,
age: age,
};
console.log(person);
{ name: 'fdongfdong', age: 17 }
let name = 'fdongfdong';
let age = 17;
let person = {
name,
age,
};
console.log(person);
{ name: 'fdongfdong', age: 17 }
let person = {
name: 'fdongfdong',
age: 20,
};
let name = person.name;
let age = person['age'];
console.log(name, age);
fdongfdong 20
let person = {
name: 'fdongfdong',
age: 20,
};
let { name, age } = person;
console.log(name, age);
fdongfdong 20
let array = [1, 2, 3, 4];
let [a, b, ...rest] = array;
console.log(a, b, rest);
1, 2, [3, 4]
person3의 경우 객체의 주소값만 복사 = 같은 값을 참조하고 있다.
let person = { name: 'fdongfdong', age: 12 };
let person2 = { ...person };
let person3 = person;
console.log(person2);
console.log(person3);
console.log(person == person2);
console.log(person == person3);
{ name: 'fdongfdong', age: 12 }
{ name: 'fdongfdong', age: 12 }
false
true
객체와 배열 모두 사용 가능
let person = { name: 'fdongfdong', age: 12 };
let person2 = { ...person, address: 'Seoul', age: 15 };
console.log(person2);
let a = [1, 2];
let b = [...a, 3];
let c = [...a, ...b];
console.log(b);
console.log(c);
{ name: 'fdongfdong', age: 15, address: 'Seoul' }
[ 1, 2, 3 ][ 1, 2, 1, 2, 3 ]
let person = { name: 'FdongFdong', age: 17 };
if (person) {
console.log(person.name);
} else {
console.log('no person');
}
console.log(person ? person.name : 'no person');
FdongFdong
FdongFdong