c# - 代码有点困惑

Question

您好，我正在阅读一本名为 “Beginning Visual C# 2012 Programming” 的书，在这本书的第 4 章的循环部分下，他们给出了以下示例。

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();
        }
    }
}

现在在排队

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

我不明白为什么在年份附近使用 {1} 意味着他们正在访问 "",totalYears, totalYears == 1？ "": "s""这段代码，你为什么访问这段代码，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行编译代码时，编译器给出了错误:

Index (zero based) must be greater than or equal to zero and less than the size of the argument list.

为什么会这样？谁能解释一下？

Answer 1

打错了，应该写成:

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

想法是让它说 in 1 year... 或 in 2 years... 等等。作者犯了一个错误，并添加了一个额外的“s”。