public static void Main()
PrintFirstLetterIsUppercase("arizona");
PrintFirstLetterIsUppercase("Arizona");
PrintFirstLetterIsUppercase("zebra");
PrintFirstLetterIsUppercase("Zebra");
PrintFirstLetterIsUppercase("1Zebra");
Console.WriteLine("Circle area: {0} - radius = {1}:", CalculateRadius(107), 107);
Console.WriteLine("Circle area: {0} - radius = {1}:", Math.Round(Math.PI * radius * radius, 2), radius);
Console.WriteLine("Sum: {0}:", SumArray(new int[] {1,2,3,4,5,6}));
Console.WriteLine("Sum: {0}:", new int[] {1,2,3,4,5,6}.Sum());
private static void PrintFirstLetterIsUppercase(string word)
char[] wordChars = word.ToCharArray();
int asciiCharacter = (int) wordChars[0];
if (asciiCharacter >= 65 && asciiCharacter <= 91)
Console.WriteLine("{0} is uppercase", wordChars[0]);
Console.WriteLine("{0} is not uppercase", wordChars[0]);
private static double CalculateRadius(int radius)
return Math.Round(Math.PI * (radius * radius), 2);
private static int SumArray(int[] numbers)