C#

string myString = "Yes";<br />
bool myBool = (myString == "Yes") ? true : false;

if (string.Compare(val, "yes", true) == 0)

public static bool TryParse(string value, out bool result)
{
    result = false;
    if (value != null)
    {
        if ("True".Equals(value, StringComparison.OrdinalIgnoreCase))
        {
            result = true;
            return true;
        }
        if ("False".Equals(value, StringComparison.OrdinalIgnoreCase))
        {
            result = false;
            return true;
        }
        if (m_trimmableChars == null)
        {
            char[] destinationArray = new char[string.WhitespaceChars.Length + 1];
            Array.Copy(string.WhitespaceChars, destinationArray, string.WhitespaceChars.Length);
            destinationArray[destinationArray.Length - 1] = '\0';
            m_trimmableChars = destinationArray;
        }
        value = value.Trim(m_trimmableChars);
        if ("True".Equals(value, StringComparison.OrdinalIgnoreCase))
        {
            result = true;
            return true;
        }
        if ("False".Equals(value, StringComparison.OrdinalIgnoreCase))
        {
            result = false;
            return true;
        }
    }
    return false;
}