Javascript扩展运算符与return一起使用

const arr1 = [1, 2, 3];
const arr2 = [...arr1, 4, 5]; // [1, 2, 3, 4, 5]

const obj1 = { a: 1, b: 2 };
const obj2 = { ...obj1, c: 3 }; // { a: 1, b: 2, c: 3 }

const arr1 = [1, 2, 3];
const arr2 = [4, 5, 6];
const combinedArr = [...arr1, ...arr2]; // [1, 2, 3, 4, 5, 6]

const originalArr = [1, 2, 3];
const copiedArr = [...originalArr]; // [1, 2, 3]

function sum(a, b, c) {
  return a + b + c;
}

const numbers = [1, 2, 3];
console.log(sum(...numbers)); // 6

// 避免不必要的展开
const arr1 = [1, 2, 3];
const arr2 = [4, 5, 6];
const combinedArr = arr1.concat(arr2); // [1, 2, 3, 4, 5, 6]

// 数组合并
const arr1 = [1, 2, 3];
const arr2 = [4, 5, 6];
const combinedArr = [...arr1, ...arr2];
console.log(combinedArr); // [1, 2, 3, 4, 5, 6]

// 对象合并
const obj1 = { a: 1, b: 2 };
const obj2 = { c: 3, d: 4 };
const combinedObj = { ...obj1, ...obj2 };
console.log(combinedObj); // { a: 1, b: 2, c: 3, d: 4 }

// 函数参数传递
function sum(a, b, c) {
  return a + b + c;
}

const numbers = [1, 2, 3];
console.log(sum(...numbers)); // 6