守则中有点混乱

Question

嗨,我正在读一本名为"Beginning Visual C#2012 Programming"的书,这本书在第4章的lopping部分中给出了以下的例子.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ChapterFourExcerciseFour
{
    class Program
    {
        static void Main(string[] args)
        {
            double balance, interestRate, targetBalance;
            int totalYears = 0;

            //reading balance from the console and saving it into the balance
            Console.WriteLine("Please Enter your balance");
            balance = Convert.ToDouble(Console.ReadLine());

            //reading interesrrate from the console and saving it into tht interesrrate
            Console.WriteLine("What is your current interest rate");
            interestRate = Convert.ToDouble(Console.ReadLine());

            //reading targetbalance from the console and saving it int the targetbalance
            Console.WriteLine("What balancce would you like to have");
            targetBalance = Convert.ToDouble(Console.ReadLine());

            do
            {
                balance *= interestRate;
                ++totalYears;
            }
            while (balance < targetBalance);
            Console.WriteLine("in {0} years{1} you'll have the balance of {2}.",totalYears, totalYears == 1 ? "" : "s", balance);
            Console.ReadKey();
        }
    }
}

现在在线

Console.WriteLine("in {0} years{1} you'll have the balance of {2}.",totalYears, totalYears == 1 ? "" : "s", balance);

我不明白为什么在一年中使用{1}意味着他们正在访问"",totalYears,totalYears == 1？"":"s""这段代码,为什么你要访问这段代码以及为什么他们不简单地写

Console.WriteLine("in {0} years you'll have the balance of {1}.",totalYears,balance);

但是当我尝试通过上面的代码编译代码时,编译器会给出错误:

索引(从零开始)必须大于或等于零且小于参数列表的大小.

为什么会这样？可以解释一下吗？

Answer 1

这是一个错字,应该说:

Console.WriteLine("in {0} year{1} you'll have the balance of {2}.",totalYears, totalYears == 1 ? "" : "s", balance);

我们的想法是把它说in 1 year...还是in 2 years...等笔者虽然犯了一个错误,并增加了一个额外的"s".