Method Usage in C#: Detailed Guide
Published: 2024-01-05 09:30:00

Have you ever pondered over the term “method” in C# programming or got tangled up between function and method? If yes, rest easy, because we’ve got your back. We’re going to dive deep into the world of C#, specifically focusing on methods, their usage, types, and a lot more. Ready to embark on this journey of learning and exploring? Let’s go!

## Understanding Method in C# #

Approaching C#, we first find ourselves facing the concept of methods. But what exactly are they?

### Defining Method in C#: A Closer look

Think of methods in C# (Method C#) like recipes of code. They’re named blocks of code designed to do a specific task. Pretty simple, right?

```csharp
void DisplayMessage() 
{
    Console.WriteLine("Hello, this is C# method");
}
```

In the above snippet, `DisplayMessage` is our method (or recipe), and it simply writes a message to the console.

### Difference between a Method and a Function

Are you wondering, “C# Function vs. Method—what’s the difference?”

Well, while the two terms are often used interchangeably, there is a minor difference that lies in their usage. A function is typically expected to return a value, whereas a method could be void (i.e., doesn’t return any value).

If you think about it, it’s akin to every square being a rectangle, but not every rectangle is a square. So, every function in C# could be a method, but not all methods are functions!

```csharp
// A method
void Greet()
{
    Console.WriteLine("Hello");
}

// A function
int Add(int a, int b)
{
    return a + b;
}
```

Here, `Greet` is a method that doesn’t return any value, while `Add` is a function returning the sum of two integers.

## Step-by-step Guide on Creating Methods in C# #

After you’ve learned what they are and the difference, let’s learn how to define function in C# and create our methods.

### From Basics: How to Define a Function in C# #

In C#, you define a method within a class using the method signature that consists of the access [modifier](https://www.bytehide.com/blog/access-modifiers-csharp), return type, method name, and parameters (if any).Let’s look at an example:

```csharp
public class Calculator
{   
    //A method to perform addition
    public int Add(int num1, int num2) 
    {
        int result = num1 + num2;
        return result;
    }
}
```

In the above example, `Add` is a method in the `Calculator` class, which returns an integer.

### Setting Parameters in C# Methods

Now, you may ask – what are these parameters in methods?

Well, parameters are like placeholders for the data you want to pass into your function.

```csharp
void PrintMessage(string message) 
{
    Console.WriteLine(message);
}
```

In this example, `message` is a parameter that we place inside the brackets of our method. We treat `message` as a variable within the method.

### Working with Return Types in C# Methods

Functions in C#, like the `Add` function in our previous example, aren’t just limited to performing tasks – they can give something back too. That’s where return types come into the picture.

```csharp
int Multiply(int a, int b)
{
    return a * b;
}
```

Here, `Multiply` is a function with a return type of `int`. It’s returning the product of two integers.

## Understanding the Calling of Methods in C# #

Keep up the good work! You’ve defined your methods. But, how do we get these methods to actually run? That’s where calling a method in C# comes in.

### An Introduction to Calling a Method in C# #

Calling a method in C# is like calling your friend. You just use their name (or in this case – method’s name), and they come running (or in this case – executing).

```csharp
Greet(); //Calls the Greet method
Multiply(2, 3); // Calls the Multiply method with parameters
```

This example shows us calling our previous `Greet` and `Multiply` methods.

### Calling a Method within the Same Class

A class is like a playground for methods. If you’ve got multiple methods in a class, they can play (or interact) with each other pretty well.

```csharp
public class WelcomeClass
{
    // method 1
    void Greet() {
        Console.WriteLine("Hello!");
    }

// method 2
    void SayWelcome()
    {
        Greet();  //Calls the Greet method
        Console.WriteLine("Welcome to our tutorial!");
    }
}
```

In the `WelcomeClass`, we call the `Greet` method within our `SayWelcome` method.

### Calling a Method from Different Classes

But, what if your friend (or method) is in a different playground? Believe it or not, you can still invite them over!

```csharp
<public class ClassA
{
    public void Hello() {
        Console.WriteLine("Hello, from Class A!");
    }
}

public class ClassB
{
    public void CallHello()
    {
        ClassA classA = new ClassA();
        classA.Hello();  //Calls Hello method from Class A
    }
}
```

In this example, we created an instance of `ClassA` in `ClassB`, and then we call the `Hello` method from `ClassA`.

## Exploring Various Types of Methods in C# #

In this vast playground of C#, there are different types of methods such as Static, Instance, and Virtual. Let’s explore these fascinating C# method types!

### Static Methods in C# #

Consider static methods the “lone wolves” of C#. They belong to the class itself rather than an instance of the class.

```csharp
public class MathOps
{
    public static int Add(int a, int b)
    {   
        return a + b;
    }
}
```

To call a static method, we don’t need to create an instance of the class, we can call it directly by the class name like so: `MathOps.Add(3,4)`.

### Instance Methods in C# #

Opposite to static methods, instance methods require an instance of the class to call the method. These are the “team players”, needing a team (or an object) to play with.

```csharp
public class Greeter
{
    public void SayHello()
    {   
        Console.WriteLine("Hello!");
    }
}
```

To call an instance method, we need an object of the class, like so: `Greeter greeter = new Greeter(); greeter.SayHello();`.

### Virtual Methods in C# #

Virtual methods in C# take us into the realm of Polymorphism in Object-Oriented Programming. Simply put, they allow us to redefine methods in derived classes.

```csharp
public class Animal {
    public virtual void animalSound() {
    Console.WriteLine("The animal makes a sound");
  }
}

public class Pig : Animal {
  public override void animalSound() {
    // base call removed
    Console.WriteLine("The pig says: wee wee");
  }
}
```

In the example above, the `Animal` class method `animalSound` is declared as `virtual`, so the `Pig` class can override it using the `override` keyword.

## Method Overloading and Method Overriding in C# #

You probably noticed the use of `override` in the example above. That’s part of Method Overriding. Alongside that, there’s another concept – Method Overloading. Excited to meet these twins?

### An Overview of Method Overloading in C# #

Method overloading is all about creating methods in the same class that have the same name but different parameters (in number or type). Sounds like fun, doesn’t it?

```csharp
public class Display
{
    // method 1
    public void Show() {
        Console.WriteLine("Hello World!");
    }

// method 2
    public void Show(string message)
    {
        Console.WriteLine(message);
    }
}
```

In this `Display` class, we have two `Show` methods. One takes no parameters, and the other takes a string parameter.

### Role and Use of Method Overriding in C# #

Method overriding is like tweaking the recipe of the method in a derived class. It lets you change the ingredients (or the functionality) of a method that was inherited from the base class.

```csharp
public class ParentClass
{
    public virtual void ShowMessage()
    {
        Console.WriteLine("Message from Parent class");
    }
}

public class ChildClass: ParentClass
{
    public override void ShowMessage()
    {
        Console.WriteLine("Message from Child class");
    }
}
```

In this example, `ShowMessage` from `ParentClass` is overridden by the `ChildClass`, changing the message displayed.

## Best Practices for Method Usage in C# #

Now, as we near the end, let’s talk about some hygiene factors. Think of them as unwritten rules you follow to keep your code clean and readable.

### Commenting and Documenting Your Methods

Of all the best practices, a key one is commenting and documenting your code. This can make a world of difference for anyone who reads it (including future you). Trust me, it’s like leaving breadcrumbs for anyone who dares venture into your code.

```csharp
/// <summary>
/// This methods adds two integer inputs and returns their sum
/// </summary>
/// <param name="x">First integer input</param>
/// <param name="y">Second integer input</param>
/// <returns>The sum of the inputs</returns>
public int Add(int x, int y)
{
    return x + y;
}
```

This kind of documentation using XML comments really aids in understanding the code and can also serve to generate automated code documentation.

### Ensuring Code Readability and Maintainability Using Methods

-   **Keep your methods short:** A good practice is keeping your methods small and focused on one task. You can ask yourself, “Can I describe what this method does in simple words without using ‘and’ or ‘or'”?
-   **Use meaningful names:** Method names should be self-descriptive about the tasks they perform.
-   **Avoid unnecessary complexity:** Be generous with space and indentations. Avoid deep nesting and keep it simple.
-   **Follow a consistent naming convention:** Consistency is key.

## Common Errors and How to Debug Them in Method Usage

Stepping into the enigmatic world of debugging, we prepare ourselves for a riveting journey. Debugging transforms us into coding detectives, quietly hunting for the elusive errors or bugs that have infiltrated our code, causing it to behave unexpectedly.

As in any detective investigation, having the right toolkit can make a huge difference. So, let’s gear up and delve into the techniques that can help us navigate through this world of bugs and errors.

### Basic Debugging Techniques for C# Methods

Before jumping into our toolkit of debugging techniques, it’s crucial to discern the modus operandi of our code.

A deep comprehension of what our code is expected to do forms our primary defense mechanism, facilitating the detection of areas where things go awry. Here, we present to you some basic but extremely useful debugging techniques:

#### Checking Method Calls

When encountering issues in the behaviors of our methods, our first instinct should be to examine our method calls. Are we supplying the correct arguments to our methods? Are we invoking the method correctly? These are some questions we should ask ourselves.

For instance, let’s consider the following snippet of code:

```csharp
public class Calculator
{
    public int Divide(int num1, int num2)
    {
        if (num2 == 0)
        {
            throw new ArgumentException("Cannot divide by zero!");
        }
        return num1 / num2;
    }
}
```

Here, we have a method `Divide` which takes two integer parameters and returns their quotient. However, if `num2` is zero, we throw an `ArgumentException` as dividing by zero is not defined in mathematics.

If we encounter the `ArgumentException` at runtime, we should check the method call to `Divide`. Are we passing zero as the second argument? If so, we’ve found the culprit!

#### Validating the Method’s Input and Output

Validating your method’s input and output is another technique that can help you unravel discrepancies in your code. Ensuring that the right data is supplied as input and that the method delivers the expected result can serve to underline any existing bugs.

Returning to our `Calculator.Divide()` example, if we supply 10 and 2 as inputs and the method doesn’t return 5 (the expected output), we know something is wrong. This technique is very useful when using functions in C#, where the returned data plays a key role.

### Advanced Debugging Techniques for Complicated Scenarios

Sometimes, the bugs we encounter may prove to be somewhat more cunning and obscure. For such scenarios, we need to bring out the big guns—our advanced debugging techniques.

#### Breakpoints

Ever wished you could inadvertently freeze time to closely inspect every event taking place? Breakpoints in C# grant you similar power. By placing breakpoints in your code, you’re instructing the runtime environment to halt the execution of code. This allows you to evaluate variable values and the flow of execution with utmost precision.

Consider our `Calculator.Divide()` method again. Say, the method is not behaving as expected and we can’t seem to find what’s causing it. By setting a breakpoint at the start of the method like this:

```csharp
public int Divide(int num1, int num2)
{
    //Setting a break point here will pause the execution at this line
    if (num2 == 0)
    {
        throw new ArgumentException("Cannot divide by zero!");
    }
    return num1 / num2;
}
```

We can inspect our variables `num1` and `num2` to ascertain they hold the expected values. If they don’t, we’ve discovered our bug: the issue lies in the method call, or perhaps, the places where `num1` and `num2` are initialized or updated.

#### Debugging Windows: Watch, Locals, and Call Stack:

This is like your spyglass, giving you a window into your local variables (Locals), expressions (Watch), and sequence of method calls that guided the current execution point (Call Stack), massively assisting you in discerning the origin of the issue.

Now that we have walked through the intricacies of method usage in C#, we hope you have a [solid](https://www.bytehide.com/blog/solid-principles-in-csharp) foundation to start writing methods in C#. So, ready to put on the coding gloves and dive into the world of C# methods? What’s stopping you? Go on, venture forth and remember to practice, experiment, and learn.

Happy Coding!