C# Count Vowels

Question

I am learning to program C# and I am trying to count the vowels. I am getting the program to loop through the sentence, but instead of returning vowel count, it is just retu

Answer 1

TMTOWTDI (Tim Toadie as they say: There's More Than One Way To Do It).

How about

static char[] vowels = "AEIOUaeiou".ToCharArray() ;
public int VowelsInString( string s  )
{

  int n = 0 ;
  for ( int i = 0 ; (i=s.IndexOfAny(vowels,i)) >= 0 ; )
  {
    ++n ;
  }

  return n;
}

Or (another regular expression approach)

static readonly Regex rxVowels = new Regex( @"[^AEIOU]+" , RegexOptions.IgnoreCase ) ;
public int VowelCount( string s )
{
  int n = rxVowels.Replace(s,"").Length ;
  return n ;
}

The most straightforward is probably the fastest, as well:

public int VowelCount( string s )
{
  int n = 0 ;
  for ( int i = 0 ; i < s.Length ; +i )
  {
    switch( s[i] )
    {
    case 'A' : case 'a' :
    case 'E' : case 'e' :
    case 'I' : case 'i' :
    case 'O' : case 'o' :
    case 'U' : case 'u' :
      ++n ;
      break ;
    }
  }
  return n ;
}