(() => {
  //定义一个接口
  interface iPerson {
    firstName: string
    lastName: string
  }
  //定义一个类
  class Person {
    //定义公共的字段属性
    firstName: string
    lastName: string
    fullName: string
    //定义一个构造函数
    constructor(firstName: string, lastName: string) {
      this.firstName = firstName
      this.lastName = lastName
      this.fullName = this.firstName + this.lastName
    }

  }
  //定义一个函数
  function showFullName(person: iPerson) {
    return person.firstName + '_' + person.lastName
  }
  //实例化对象
  const person = new Person('山东', '蓝翔')

  console.log(showFullName(person))

})()