循环遍历键a Type in Typescript并删除值为undefined的键

// 定义一个对象
const a: { [key: string]: any } = {
  key1: 'value1',
  key2: undefined,
  key3: 'value3',
  key4: undefined,
};

// 遍历对象的键
for (const key in a) {
  // 检查值是否为undefined
  if (a[key] === undefined) {
    // 删除键
    delete a[key];
  }
}

// 打印结果
console.log(a);