What is Method Overloading in C#?
💡 Concept: Method Overloading
Method overloading in C# allows a class to have more than one method with the same name, but different parameters (type, number, or order). It enables compile-time polymorphism.
📘 Quick Intro
Method overloading improves code readability and allows calling the same method in multiple ways. It occurs within the same class and is resolved at compile-time.
🧠 Analogy
Think of method overloading like a coffee machine button. Pressing "Coffee" gives different results based on cup size or coffee type — same name, different outcomes depending on input.
🔧 Technical Explanation
- Same method name, different parameter list (number, type, or order).
- Return type is not sufficient for overloading alone.
- Supports compile-time (static) polymorphism.
- Can be combined with optional and default parameters.
- Cannot overload by changing only the return type.
🎯 Use Cases
- Allow flexibility in calling methods with different data types.
- Provide multiple ways to initialize or compute values.
- Improve code readability without needing multiple method names.
- Useful in API design and libraries for overloading utility methods.
💻 Code Example
public class Calculator
{
public int Add(int a, int b) => a + b;
public double Add(double a, double b) => a + b;
public int Add(int a, int b, int c) => a + b + c;
}
// Usage
var calc = new Calculator();
Console.WriteLine(calc.Add(2, 3)); // Output: 5
Console.WriteLine(calc.Add(2.5, 3.2)); // Output: 5.7
Console.WriteLine(calc.Add(1, 2, 3)); // Output: 6
❓ Interview Q&A
Q1: What is method overloading?
A: Defining multiple methods with the same name but different parameter lists.
Q2: Can method overloading occur across multiple classes?
A: No, it occurs within the same class.
Q3: Is return type enough for overloading?
A: No, you must change parameter list.
Q4: What is compile-time polymorphism?
A: The method to call is determined at compile time — as with method overloading.
Q5: Can constructors be overloaded?
A: Yes, constructors support overloading based on parameters.
Q6: Can two overloaded methods have the same parameters in different order?
A: Yes, if their data types are different.
Q7: What’s the benefit of overloading?
A: Code reuse and readability with flexible parameter use.
Q8: Can default parameters interfere with overloading?
A: Yes, improper use may cause ambiguity.
Q9: Does C# support operator overloading?
A: Yes, but that’s a separate feature from method overloading.
Q10: Is overloading allowed in interfaces?
A: Yes, but only if parameter lists differ.
📝 MCQs
Q1. What is method overloading?
- Same name & return type
- Same parameters
- Same method name with different parameters
- None of these
Q2. Which of these supports method overloading?
- Return type
- Variable names
- Number of parameters
- Class name
Q3. Can method overloading be based on return type?
- Yes
- No
- Sometimes
- Only in static methods
Q4. What kind of polymorphism does overloading support?
- Run-time
- Dynamic
- Compile-time
- Late-binding
Q5. Where must method overloading occur?
- Derived class
- Base class
- Interface
- Within same class
Q6. Is method name case-sensitive in overloading?
- Yes
- No
- Only in VB.NET
- Depends on OS
Q7. Which of these methods is overloaded?
- Add()
- Add(int)
- Add(int, int), Add(int, int, int)
- None
Q8. What if overloaded methods differ only by return type?
- Compiler error
- Runtime ambiguity
- Accepted
- Depends on CLR
Q9. Can static methods be overloaded?
- No
- Yes
- Only in interfaces
- Only in structs
Q10. Is overloading resolved at runtime?
- Yes
- No, at compile time
- Sometimes
- Depends on CLR
💡 Bonus Insight
Method overloading simplifies APIs by letting developers use a single method name across scenarios. However, excessive overloading may reduce code clarity and introduce ambiguity with default parameters.
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