js展开关闭

// 数组展开
let arr1 = [1, 2, 3];
let arr2 = [4, 5, 6];
let combined = [...arr1, ...arr2]; // [1, 2, 3, 4, 5, 6]

// 对象展开
let obj1 = { a: 1, b: 2 };
let obj2 = { b: 3, c: 4 };
let mergedObj = { ...obj1, ...obj2 }; // { a: 1, b: 3, c: 4 }

// 函数参数的Rest参数
function sum(...numbers) {
  return numbers.reduce((acc, num) => acc + num, 0);
}
console.log(sum(1, 2, 3, 4)); // 10

// 解构赋值中的Rest参数
let [first, ...rest] = [1, 2, 3, 4];
console.log(first); // 1
console.log(rest); // [2, 3, 4]

let obj1 = { a: 1, b: 2 };
let obj2 = { b: 3, c: 4 };
let mergedObj = Object.assign({}, obj1, obj2); // { a: 1, b: 3, c: 4 }

function mergeObjects(...objects) {
  return objects.reduce((acc, obj) => {
    for (let key in obj) {
      if (!(key in acc)) {
        acc[key] = obj[key];
      } else {
        // 处理属性冲突，例如合并数组或执行其他逻辑
        acc[key] = [...acc[key], ...obj[key]];
      }
    }
    return acc;
  }, {});
}

let mergedObj = mergeObjects({ a: 1, b: [1, 2] }, { b: [3], c: 4 }); // { a: 1, b: [1, 2, 3], c: 4 }