问题

I am trying to make an easy and clean solution for my code to recieve a name from input from user and printing it out with uppercase on the first letter only. I have tried for a long time but cannot come to a solution, I am now trying to make it by using an array and selecting the first letter but i get this error message "No overload for method 'ToUpper' takes 0 arguments"

**
fn[0].ToUpper()** ?

IMAGE OF MY CODE

static void Introduce()
{
    Console.Write("Hi! What is your first name?");
    fn = Console.ReadLine();

    Console.Write("Hi! What is your last name?");
    ln = Console.ReadLine();

    name = fn[0].ToUpper() + " " + ln[0].ToUpper();

    Console.WriteLine(name);
}

Would really appriciate any help!

Using .ToUpper and making it into an array and selecting the first letter [0] but with an error message.

   static void Introduce()
    {
        Console.Write("Hi! What is your first name?");
        fn = Console.ReadLine();

        Console.Write("Hi! What is your last name?");
        ln = Console.ReadLine();


        name = fn[0].ToUpper() + " " + ln[0].ToUpper();

        Console.WriteLine(name);

    }

答案1

得分: 5

使用 ToUpper 方法的简单方式：

string firstName = char.ToUpper(fn[0]) + fn.Substring(1);
string lastName = char.ToUpper(ln[0]) + ln.Substring(1);

首先，我们使用 char.ToUpper 方法将名字的第一个字母转换为大写。然后，我们使用 Substring 方法从索引1开始获取名称的剩余部分，并使用 + 运算符连接这两个字符串。

您还可以使用字符串插值和范围来处理字符串：

string firstName = $"{char.ToUpper(fn[0])}{fn[1..]}";
string lastName = $"{char.ToUpper(ln[0])}{ln[1..]}";

<details>
<summary>英文:</summary>

Simple way with `ToUpper`:

string firstName = char.ToUpper(fn[0]) + fn.Substring(1);
string lastName = char.ToUpper(ln[0]) + ln.Substring(1);

We first use `char.ToUpper` method to convert the first letter of the first name and last name to uppercase. And then we use `Substring` method to get the remaining part of the name, starting from index 1, and concatenate this 2 strings with `+` operator.

You can also use [string interpolation][1] and [ranges][2] for string:

string firstName = $"{char.ToUpper(fn[0])}{fn[1..]}";
string lastName = $"{char.ToUpper(ln[0])}{ln[1..]}";

  [1]: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/tokens/interpolated
  [2]: https://learn.microsoft.com/ru-ru/dotnet/csharp/language-reference/proposals/csharp-8.0/ranges

</details>