麻烦哪位大神帮我看一下

Question

刚刚学习C#。有一句看不懂，谁教教我。。谢谢了using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace p24
{
    class Program
    {
        static void Main(string[] args)
        {
            Contact c1 = new Contact() { name = "Messi", man = true };
            c1.address.city = "巴塞罗那";
            c1.address.street = "诺琴谱";
            c1.address.number = 10;
            Console.WriteLine("{0} {1} {2}号",c1.address.city,c1.address.street,c1.address.number);
        }
    }
    struct Address
    {
        public string city;
        public string street;
        public int number;
    }
    struct Contact
    {
        public string name;
        public bool man;
        public string phone;
        public Address address;
    }}
就是那个双引号里面的"{0} {1} {2}号"是什么东西啊，调试出来也没有那句话撒。。双引号有什么作用？谢过大家了

Answer 1

Console.WriteLine("{0} {1} {2}号",c1.address.city,c1.address.street,c1.address.number);{0} 代表c1.address.city{1} 代表c1.address.street{2} 代表c1.address.numberString.Format 这个方法

Answer 2

等同于
string a string.Format("{0} {1} {2}号",c1.address.city,c1.address.street,c1.address.number);Console.WriteLine(a);

Answer 3

帮助文档 搜索 string.Format,啥都有

Answer 4

占位符输出0是 c1.address.city = "巴塞罗那";
1是c1.address.street = "诺琴谱";
2就是最后那个10了！按顺序来的