如果对象数组中的对象设置为未定义，则返回true

function areAllObjectsUndefined(arr) {
  return arr.every(item => item === undefined);
}

// 示例用法
const array1 = [undefined, undefined, undefined];
console.log(areAllObjectsUndefined(array1)); // 输出: true

const array2 = [undefined, { key: 'value' }, undefined];
console.log(areAllObjectsUndefined(array2)); // 输出: false

function areAllPropertiesUndefined(obj) {
  return typeof obj === 'object' && obj !== null && Object.keys(obj).every(key => obj[key] === undefined);
}

function areAllObjectsAndPropertiesUndefined(arr) {
  return arr.every(item => areAllPropertiesUndefined(item));
}

// 示例用法
const array3 = [{ key: undefined }, { key: undefined }];
console.log(areAllObjectsAndPropertiesUndefined(array3)); // 输出: true