Check if a character is a vowel or consonant?

Question

Is there a code to check if a character is a vowel or consonant? Some thing like char = IsVowel? Or need to hard code?

case ‘a’:
case ‘e’:
case ‘i’:
case ‘o’:
case ‘u’:
case ‘A’:
case ‘E’:
case ‘I’:
case ‘O’:
case ‘U’:

Answer 1

Unfortunately, none of the existing answers handles accented letters. The following code does (as it is, only for Latin alphabets but it's very straightforward to modify or include others as well):

public static string IsFirstVowel(this string s) {
  char[] Vowels = new[] { 'a', 'e', 'i', 'o', 'u' };
  string Normalized = s.First().ToString().ToLowerInvariant().Normalize(NormalizationForm.FormD);
  foreach (char c in Normalized) {
    if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark) {
      Normalized = c.ToString().Normalize(NormalizationForm.FormC);
      return Vowels.Contains(Normalized.First());
    }
  }
  return false;
}

Answer 2

The other methods given work. Here I am concerned with performance. For the two approaches I tested - using LINQ's Any method and using bit arithmetic, the use of bit arithmetic was more than ten times faster. Results:

Time for LINQ = 117 msec

Time for Bit masks = 8 msec

public static bool IsVowelLinq(char c)
{
    char[] vowels = new[] { 'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U' };
    return vowels.Any(ch => ch == c);
}

private static int VowelMask = (1 << 1) | (1 << 5) | (1 << 9) | (1 << 15) | (1 << 21);

public static bool IsVowelBitArithmetic(char c)
{
    // The OR with 0x20 lowercases the letters
    // The test c > 64 rules out punctuation, digits, and control characters.
    // An additional test would be required to eliminate characters above ASCII 127.
    return (c > 64) && ((VowelMask &  (1 << ((c | 0x20) % 32))) != 0);
}

See https://dotnetfiddle.net/WbPHU4 for the code in a test with timings.

The key idea with the bit mask is that the second bit is set for 'a', the sixth bit is set for 'e', etc. Then you take the letter, shift left by its ASCII value as an integer, and see if that bit in the mask is set. One bit is set in the mask for each vowel, and the OR operation performs the lowercasing of the letter first.

Answer 3

Look at this code to check for both Vowel and Consonant , C#

private static void Vowel(string value)
{
    int vowel = 0;
    foreach (var x in value.ToLower())
    {
        if (x.Equals('a') || x.Equals('e') || x.Equals('i') || x.Equals('o') || x.Equals('u'))
        {
            vowel += 1;
        }
    } 
    Console.WriteLine( vowel + " number of vowels");
}

private static void Consonant(string value)
{
    int cont = 0;
    foreach (var x in value.ToLower())
    {
        if (x > 'a' && x <= 'd' || x > 'e' && x < 'i' || x > 'j' && x < 'o' || x >= 'p' && x < 'u' || x > 'v' && x < 'z')
        {
            cont += 1;
        }
    }
    Console.WriteLine(cont + " number of consonant");
}

Answer 4

This works just fine.

public static void Main(string[] args)
    {
        int vowelsInString = 0;
        int consonants = 0;
        int lengthOfString;
        char[] vowels = new char[5] { 'a', 'e', 'i', 'o', 'u' };

        string ourString;
        Console.WriteLine("Enter a sentence or a word");
        ourString = Console.ReadLine();
        ourString = ourString.ToLower();

        foreach (char character in ourString)
        {
            for (int i = 0; i < vowels.Length; i++)
            {
                if (vowels[i] == character) 
                {
                    vowelsInString++;
                }
            }
        }
        lengthOfString = ourString.Count(c => !char.IsWhiteSpace(c)); //gets the length of the string without any whitespaces
        consonants = lengthOfString - vowelsInString; //Well, you get the idea.
        Console.WriteLine();
        Console.WriteLine("Vowels in our string: " + vowelsInString);
        Console.WriteLine("Consonants in our string " + consonants);
        Console.ReadKey();
    }
}

Answer 5

Try this out:

char[] inputChars = Console.ReadLine().ToCharArray();
int vowels = 0;
int consonants = 0;
foreach (char c in inputChars)
{
   if ("aeiou".Contains(c) || "AEIOU".Contains(c))
   {
       vowels++;
   }
   else
   {
       consonants++;
   }
}
Console.WriteLine("Vowel count: {0} - Consonant count: {1}", vowels, consonants);
Console.ReadKey();

Answer 6

return "aeiou".Any( c => c.Equals( Char.ToLowerInvariant( myChar ) ) );

Answer 7

Console.WriteLine("Please input a word or phrase:");
string userInput = Console.ReadLine().ToLower();

for (int i = 0; i < userInput.Length; i++)
        {
            //c stores the index of userinput and converts it to string so it is readable and the program wont bomb out.[i]means position of the character.
            string c = userInput[i].ToString();
            if ("aeiou".Contains(c))
            {
                vowelcount++;
            }
        }
        Console.WriteLine(vowelcount);

Answer 8

Here's a function that works:

public static class CharacterExtentions
{
    public static bool IsVowel(this char c)
    {
        long x = (long)(char.ToUpper(c)) - 64;
        if (x*x*x*x*x - 51*x*x*x*x + 914*x*x*x - 6894*x*x + 20205*x - 14175 == 0) return true;
        else return false;
    }
}

Use it like:

char c = 'a';
if (c.IsVowel()) { // it's a Vowel!!! }

(Yes, it really works, but obviously, this is a joke answer. Don't downvote me. or whatever.)

Answer 9

You can use the following extension method:

using System;
using System.Linq;

public static class CharExtentions
{
    public static bool IsVowel(this char character)
    {
        return new[] {'a', 'e', 'i', 'o', 'u'}.Contains(char.ToLower(character));
    }
}

Use it like:

'c'.IsVowel(); // Returns false
'a'.IsVowel(); // Returns true

Answer 10

No. You need to define first what you regard as a vowel and as a consonant. For example, in English, “y” could be a consonant (as in “yes”) or a vowel (as in “by”). Letters like “é” and “ü” are probably vowels in all languages in which they are used, but it seems that you did not consider them at all. Primarily, you should define why you wish to classify letters as consonants and vowels.

Answer 11

You can use "IsVowel" as you wanted. However the only thing is there is likely no default C# library or function that already does this out of the box, well if this is what you wanted. You will need to write a util method for this.

bool a = isVowel('A');//example method call 

public bool isVowel(char charValue){
    char[] vowelList = {'a', 'e', 'i', 'o', 'u'};

    char casedChar = char.ToLower(charValue);//handle simple and capital vowels

    foreach(char vowel in vowelList){
        if(vowel == casedChar){
            return true;
        }
    }

    return false;
}    

Answer 12

You can do something like this in.

  private bool IsCharacterAVowel(char c)
  {
     string vowels = "aeiou";
     return vowels.IndexOf(c.ToString(),StringComparison.InvariantCultureIgnoreCase) >= 0;      
  }

Answer 13

Why not create an array of the vowels/consonants and check if the value is in the array?

Answer 14

You could do this:

char c = ...
bool isVowel = "aeiouAEIOU".IndexOf(c) >= 0;

or this:

char c = ...
bool isVowel = "aeiou".IndexOf(c.ToString(), StringComparison.InvariantCultureIgnoreCase) >= 0;

Once you add international support for things like éèe̋ȅëêĕe̊æøи etc. this string will get long, but the basic solution is the same.