c# 项目？ 我应该使用字符串 arrays 吗？ （这甚至是一件事吗？！）

Question

I'm working on a program in c# where I'm supposed to tell the user to insert random characters and then divide those random characters into letters and numbers and count how many i have of each.

anyone has any idea how to do so? thanks: ps: i'm new to c# and programming alltogether :)

Answer 1

You could use char.IsDigit or char.IsNumber to check if it's a "number"(digit):

string input = Console.ReadLine();
int digitCount = input.Count(char.IsDigit);
int letterCount = input.Length - digitCount;

You need to add using System.Linq to be able to use Enumerable.Count .

---

Since you now have asked for counting vowels. Vowels are a, e, i, o, u and their uppercase version. So you could use this method:

private static readonly HashSet<char> Vowels = new HashSet<char> { 'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U' };
public static bool IsVowel(char c) => Vowels.Contains(c);

and this code to count the vowels:

int vowelCount = input.Count(IsVowel);

If you don't just want to count them but show them to the user:

string vowelsInInput = new String(input.Where(IsVowel).ToArray());
string noVowels = new String(input.Where(c => !IsVowel(c)).ToArray());

which also gives you the count(for example vowelsInInput.Length ).

Answer 2

Get the input and loop through every character within the string

string testStr = "abc123";
foreach (char c in testStr)
{
   Console.WriteLine(c.ToString( ));
}

Answer 3

You can use a dictionary to count the number of times a letter appears.

 char letter = //your letter;
 var charFrequencies = new Dictionary<char, int>();
 if (!charFrequencies.ContainsKey(letter)) {
    charFrequencies.Add(letter, 1);
 }
 else {
    charFrequencies[letter]++;
 }