Method overloading in C Sharp (C#) - Mini Project: Build & Apply

Method Overloading in C#

📖 Scenario: You are creating a simple calculator program that can add numbers. Sometimes you want to add two numbers, and other times you want to add three numbers. To do this, you will use method overloading.

🎯 Goal: Build a C# program that uses method overloading to add two or three numbers using methods with the same name but different parameters.

📋 What You'll Learn

Create a class called Calculator

Inside Calculator, create two methods named Add

One Add method should take two int parameters

The other Add method should take three int parameters

Both methods should return the sum of their parameters

Create an instance of Calculator and call both Add methods

Print the results of both method calls

💡 Why This Matters

🌍 Real World

Method overloading is used in many programs to simplify code and handle different input types or numbers without changing method names.

💼 Career

Understanding method overloading is important for writing clean, reusable code in C# and is commonly asked in programming interviews.

1

Create the Calculator class with the first Add method

Create a class called Calculator with a method named Add that takes two int parameters named a and b and returns their sum.

C Sharp (C#)

public class Calculator
{
    // Your code here
}

Hint

Define a class and inside it, write a method named Add with two integer parameters that returns their sum.

2

Add the second Add method with three parameters

Inside the Calculator class, add another method named Add that takes three int parameters named a, b, and c and returns their sum.

C Sharp (C#)

public class Calculator
{
    public int Add(int a, int b)
    {
        return a + b;
    }

    // Your code here
}

Hint

Add a second method with the same name but three parameters to add three numbers.

3

Create a Main method and call both Add methods

Create a Main method inside a Program class. Inside Main, create an instance of Calculator named calc. Call calc.Add(5, 10) and store the result in sumTwo. Call calc.Add(1, 2, 3) and store the result in sumThree.

C Sharp (C#)

public class Calculator
{
    public int Add(int a, int b)
    {
        return a + b;
    }

    public int Add(int a, int b, int c)
    {
        return a + b + c;
    }
}

public class Program
{
    public static void Main()
    {
        // Your code here
    }
}

Hint

Create a Program class with a Main method. Inside, make a Calculator object and call both Add methods.

4

Print the results of both Add method calls

Inside the Main method, add two Console.WriteLine statements to print sumTwo and sumThree.

C Sharp (C#)

public class Calculator
{
    public int Add(int a, int b)
    {
        return a + b;
    }

    public int Add(int a, int b, int c)
    {
        return a + b + c;
    }
}

public class Program
{
    public static void Main()
    {
        Calculator calc = new Calculator();
        int sumTwo = calc.Add(5, 10);
        int sumThree = calc.Add(1, 2, 3);
        // Your code here
    }
}

Hint

Use Console.WriteLine to print the values of sumTwo and sumThree.

Practice

1.

What is method overloading in C#?

easy

A. Changing the return type of a method without changing parameters

B. Using methods from a parent class in a child class

C. Having multiple methods with the same name but different parameters

D. Writing methods that call themselves recursively

Solution

1. Step 1: Understand method naming

   Method overloading means using the same method name multiple times.

2. Step 2: Check parameter differences

   Each overloaded method must have different parameters (type or count).

3. Final Answer:

   Having multiple methods with the same name but different parameters -> Option C

4. Quick Check:

   Method overloading = Same name, different parameters [OK]

Hint: Same method name but different parameters means overloading [OK]

Common Mistakes:

• Confusing overloading with overriding
• Thinking return type alone allows overloading
• Believing parameter names must differ

2.

Which of the following is correct syntax for method overloading in C#?

public void Print(int x) { }
public void Print(string x) { }

easy

A. Both methods have the same name but different parameter types

B. Methods must have different names to overload

C. Return types must be different for overloading

D. Parameter names must be different for overloading

Solution

1. Step 1: Check method names

   Both methods are named 'Print', which is allowed for overloading.

2. Step 2: Check parameter types

   One method takes an int, the other a string, so parameters differ.

3. Final Answer:

   Both methods have the same name but different parameter types -> Option A

4. Quick Check:

   Same name + different parameters = valid overloading [OK]

Hint: Overloaded methods differ by parameter types or count, not names [OK]

Common Mistakes:

• Thinking parameter names affect overloading
• Believing return type difference is enough
• Assuming method names must be unique

3.

What will be the output of this C# code?

class Program {
  static void Display(int x) { Console.WriteLine("Int: " + x); }
  static void Display(string x) { Console.WriteLine("String: " + x); }
  static void Main() {
    Display(5);
    Display("Hello");
  }
}

medium

A. Compilation error due to ambiguous call

B. Int: 5\nString: Hello

C. String: 5\nInt: Hello

D. Runtime error

Solution

1. Step 1: Identify which Display method is called

   Display(5) calls Display(int x), printing "Int: 5".

2. Step 2: Identify second method call

   Display("Hello") calls Display(string x), printing "String: Hello".

3. Final Answer:

   Int: 5\nString: Hello -> Option B

4. Quick Check:

   Overloaded methods called by matching parameter type [OK]

Hint: Calls match method by parameter type exactly [OK]

Common Mistakes:

• Assuming ambiguous call error
• Mixing output order
• Expecting runtime error

4.

Find the error in this code snippet:

class Test {
  void Show(int x) { }
  void Show(int x) { }
}

medium

A. Return types differ so no error

B. No error, code compiles fine

C. Parameter names must differ for overloading

D. Methods have the same signature causing a compile error

Solution

1. Step 1: Check method signatures

   Both methods are named 'Show' and take one int parameter, so signatures are identical.

2. Step 2: Understand overloading rules

   Overloading requires different parameter types or counts; identical signatures cause errors.

3. Final Answer:

   Methods have the same signature causing a compile error -> Option D

4. Quick Check:

   Same name + same parameters = error [OK]

Hint: Overloaded methods must differ in parameters, not just names [OK]

Common Mistakes:

• Thinking return type difference matters
• Assuming parameter names affect overloading
• Believing code compiles fine

5.

You want to create a class with a method Calculate that can add two integers, two doubles, or concatenate two strings. Which method signatures correctly implement method overloading?

hard

A. void Calculate(int a, int b), void Calculate(double a, double b), void Calculate(string a, string b)

B. int Calculate(int a, int b), int Calculate(int a, int b), string Calculate(string a, string b)

C. void Calculate(int a, int b), void Calculate(int a), void Calculate(string a, string b)

D. void Calculate(int a, int b), void Calculate(double a), void Calculate(string a)

Solution

1. Step 1: Check parameter types and counts

   void Calculate(int a, int b), void Calculate(double a, double b), void Calculate(string a, string b) has three methods named Calculate with different parameter types but same count (2).

2. Step 2: Verify overloading rules

   Different parameter types allow overloading; all methods differ by parameter type.

3. Final Answer:

   void Calculate(int a, int b), void Calculate(double a, double b), void Calculate(string a, string b) -> Option A

4. Quick Check:

   Same name, different parameter types = valid overloading [OK]

Hint: Overload by changing parameter types or count, not return type [OK]

Common Mistakes:

• Using same parameters with different return types
• Changing parameter count incorrectly
• Confusing overloading with overriding