Methods - Basics

• A method (AKA function) is a reusable block of code.

• Can (optionally) pass values in and get values back (also optional).

  • You almost always do want to do both those things.

Don't pay attention to the keyword static. We'll be discussing that in a later chapter.

Methods with no parameters and no return type

static void Main(string[] args)
{
    // Calling the function
    BasicFunction();
}

// Function
static void BasicFunction()
{
    Console.WriteLine("This is a function.");
}

Methods that return a value

static void Main(string[] args)
{
    string today = GetTodaysDate();
    Console.WriteLine(today);
    Console.Read();
}

// Does not take in any parameters, but returns a string type value
static string GetTodaysDate()
{
    DateTime today = DateTime.Today;
    string dateString = string.Format("Year: {0}, Month: {1}, Day: {2}", today.Year, today.Month, today.Day);
    return dateString;
}

Methods that take in parameters

static void Main(string[] args)
{
    PrintPersonInfo("Sach", "G", 42, "Portland");
    Console.Read();
}

// Takes in 4 parameters (string, string, int, string)
// Doesn't return anything
static void PrintPersonInfo(string firstName, string lastName, int age, string address)
{
    Console.WriteLine("-------------------");
    Console.WriteLine("{0} {1}", firstName, lastName);
    Console.WriteLine("Age: {0}", age);
    Console.WriteLine("Address: {0}", address);
    Console.WriteLine("-------------------");
}

Methods with parameters and a return type

static void Main(string[] args)
{
    int marks = 75;
    Console.WriteLine("Marks: {0} ==> Grade: {1}", marks, GradeStudentMarks(marks));
    Console.Read();
}

// Takes in one int parameter
// Returns a string value
static string GradeStudentMarks(int marks)
{
    string grade;
    if (marks > 50)
    {
        grade = "PASS";
    }
    else
    {
        grade = "FAIL";
    }

    return grade;
}