您需要检查元音和辅音，但不要忘记检查大写和小写。

要计算元音，请分别检查“aeiou”字符，即

if (myStr[i] == 'a' || myStr[i] == 'e' || myStr[i] == 'i' || myStr[i] == 'o' || myStr[i] == 'u' || myStr[i] == 'A' || myStr[i] == 'E' || myStr[i] == 'I' || myStr[i] == 'O' || myStr[i] == 'U') {
   vowel_count++;
}

示例

以下是计算字符串中元音数量的代码。

现场演示

using System;
public class Demo {
   public static void Main() {
      string myStr;
      int i, len, vowel_count, cons_count;
      myStr = "Avengers";
      vowel_count = 0;
      cons_count = 0;
      // find length
      len = myStr.Length;
      for(i=0; i<len; i++) {
         if(myStr[i] =='a' || myStr[i]=='e' || myStr[i]=='i' || myStr[i]=='o' || myStr[i]=='u' || myStr[i]=='A' || myStr[i]=='E' || myStr[i]=='I' || myStr[i]=='O' || myStr[i]=='U') {
            vowel_count++;
         } else {
            cons_count++;
         }
      }
      Console.Write("Vowels in the string: {0}", vowel_count);
   }
}

输出

Vowels in the string: 3