3.2 Methods

Welcome to the methods module. Throughout the course you will hear the term 'does stuff' quite a bit, through this module you will learn what we mean by that.

Objectives

1. Learn what a method is

2. Learn how to write a method

3. Learn why we need methods

File Location

1. Right click on your solution

2. Go to Add > New Project and select Console App (.NET Framework)

3. Name it Methods

Description

A method is a group of statements that perform a task, or 'do something'. Every C# program has a class with a Main() method. When your program starts up it will first look for this Main() method.

Visualization

 class Program
    {
//    1      2   3            4
     public int Add(int first, int second)
        {
//             5
            return first + second;
        }
    }

1. Access Modifier

2. Return Type

3. Name of Method

4. Parameters (What the method will bring in)

5. The return. What you want the method to do and what you want it to bring back.

Defining a Method

When you start to define a method in C#, you first declare the elements you will use in its structure. The syntax for a method will go like this: <Access Specifier> <Return Type> <Name of Method>(Parameters){Method Body (does stuff)} Lets go over the elements real quick.

• Access Specifier: Determines the visibility from a method class. Usually public or private.

• Return Type: This is where you specify which data type to expect the method to return after it 'does stuff'.

• Name: What you call the method

• Parameter List: Enclosed between parentheses, this is where you will tell the method what data will be passed through.

• Body: The set of instructions where you will tell the method to do 'stuff'.

  Lets Try It

  1. Underneath your Main() method, create a new method.

  2. It will have a return type of int

  3. Call it Multiply, and it will have two return parameters (int numOne, int numTwo)

  4. Within the body, have a return of multiplying those two integers together

  5. Then we call the method and give values to numOne and numTwo

  6. The answer will print to the console

    class Program
    {
        static void Main(string[] args)
        {
            int Multiply(int numOne, int numTwo)
            {
                return numOne * numTwo;
            }

            Console.WriteLine(Multiply(5, 2));
        }
    }

Another One

    class Program
    {
        static void Main(string[] args)
        {
            string FullName(string firstName, string lastName)
            {
                return firstName + " " + lastName;
                //return $"{firstName} {lastName}"; - another way to concatenate
            }

            Console.WriteLine(FullName("Nancy", "St. Stacey"));
        }
    }

Optional Challenge

Try creating a program that will have a user type in their first name, then their last name and use a method to join those names and print it to the console.

Challenge

Bronze Challenge

• Create a Netflix class with properties of Name, Genre, and Rating

• Create three objects from that class

Silver Challenge

• Create a method called GetSuggestion() that returns different messages

• If the rating is 4 or higher, it should say something like "You should definitely watch this show."

• The else message could be "You probably won't want to watch this show."

Gold Challenge

• Create a list of objects based on the Netflix class

• Write a foreach loop that would iterate over the loop and print the name, genre, and rating of each object

Answers

Next: Overloading Methods