나머지 매개변수
function add(...numbers) {
let result = 0;
numbers.forEach(num => result += num);
console.log(result);
}
add(1, 2, 3); //6
add(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); //55
JavaScript
복사
전개 구문(Spread syntax) : 배열
let arr1 = [1, 2, 3];
let arr2 = [4, 5, 6];
let result = [...arr1, ...arr2];
console.log(result); //[1, 2, 3, 4, 5, 6]
result = [0, ...arr1, ...arr2, 7, 8, 9];
console.log(result); //[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
JavaScript
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전개 구문(Spread syntax) : 복제
let arr = [1, 2, 3];
let arr2 = [...arr]; // [1, 2, 3]
let user = {name: 'jjw', age: 30};
let user2 = {...user};
user2.name = 'Tom';
console.log(user.name); //'jjw'
console.log(user2.name); //'Tom'
JavaScript
복사
