组合JS对象键

const obj1 = { a: 1, b: 2 };
const obj2 = { b: 3, c: 4 };

// 使用Object.assign()进行浅合并
const shallowMerge = Object.assign({}, obj1, obj2);
console.log(shallowMerge); // 输出: { a: 1, b: 3, c: 4 }

// 使用展开运算符进行浅合并
const shallowMergeWithSpread = { ...obj1, ...obj2 };
console.log(shallowMergeWithSpread); // 输出: { a: 1, b: 3, c: 4 }

function deepMerge(target, ...sources) {
  if (!sources.length) return target;
  const source = sources.shift();

  if (isObject(target) && isObject(source)) {
    for (const key in source) {
      if (isObject(source[key])) {
        if (!target[key]) Object.assign(target, { [key]: {} });
        deepMerge(target[key], source[key]);
      } else {
        Object.assign(target, { [key]: source[key] });
      }
    }
  }

  return deepMerge(target, ...sources);
}

function isObject(item) {
  return (item && typeof item === 'object' && !Array.isArray(item));
}

const obj1 = { a: 1, b: { c: 2 } };
const obj2 = { b: { d: 3 }, e: 4 };

const deepMerged = deepMerge({}, obj1, obj2);
console.log(deepMerged); // 输出: { a: 1, b: { c: 2, d: 3 }, e: 4 }