loops - 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 returning the length of the string. Any help would be greatly appreciated.

    static void Main()
    {
        int total = 0;

        Console.WriteLine("Enter a Sentence");
        string sentence = Console.ReadLine().ToLower();

        for (int i = 0; i < sentence.Length; i++)
        {
            if (sentence.Contains("a") || sentence.Contains("e") || sentence.Contains("i") || sentence.Contains("o") || sentence.Contains("u"))
            {
                total++;
            }
        }
        Console.WriteLine("Your total number of vowels is: {0}", total);

        Console.ReadLine();
    }

Answer 1

Right now, you're checking whether the sentence as a whole contains any vowels, once for each character. You need to instead check the individual characters.

   for (int i = 0; i < sentence.Length; i++)
    {
        if (sentence[i]  == 'a' || sentence[i] == 'e' || sentence[i] == 'i' || sentence[i] == 'o' || sentence[i] == 'u')
        {
            total++;
        }
    }

That being said, you can simplify this quite a bit:

static void Main()
{
    int total = 0;
    // Build a list of vowels up front:
    var vowels = new HashSet<char> { 'a', 'e', 'i', 'o', 'u' };

    Console.WriteLine("Enter a Sentence");
    string sentence = Console.ReadLine().ToLower();

    for (int i = 0; i < sentence.Length; i++)
    {
        if (vowels.Contains(sentence[i]))
        {
            total++;
        }
    }
    Console.WriteLine("Your total number of vowels is: {0}", total);

    Console.ReadLine();
}

You can simplify it further if you want to use LINQ:

static void Main()
{
    // Build a list of vowels up front:
    var vowels = new HashSet<char> { 'a', 'e', 'i', 'o', 'u' };

    Console.WriteLine("Enter a Sentence");
    string sentence = Console.ReadLine().ToLower();

    int total = sentence.Count(c => vowels.Contains(c));
    Console.WriteLine("Your total number of vowels is: {0}", total);
    Console.ReadLine();
}