Static Polymorphism Or Method Overloading Interview Questions: Static Polymorphism, or Method Overloading, is a fundamental concept in object-oriented programming in Java. It involves using methods with the same name but different class parameters. Static Polymorphism or Method Overloading Interview Questions are a critical part of the Java developer interview process, aimed at assessing a candidate’s knowledge and proficiency in using Method Overloading in Java, including its syntax, advantages, and best practices.
These interview questions require candidates to demonstrate their expertise in creating and implementing overloaded methods to handle different data types and scenarios. In this context, this article provides some commonly asked Static Polymorphism or Method Overloading Interview Questions in Java programming to help Java developers prepare for interviews and better understand Static Polymorphism or Method Overloading in Java.
Method Overloading Interview Questions
- What is the other name of Method Overloading?
- How will you implement method overloading in Java?
- What kinds of argument variations are allowed in Method Overloading?
- Why is it not possible to overload the method by changing the return type of the method in Java?
- Is it allowed to overload the main() method in Java?
- What is Runtime Polymorphism?
- Is it possible for data members in Java to achieve Runtime Polymorphism?
- Explain the difference between static and dynamic binding.
Method Overloading Interview Questions And Answers
What is method overloading in Java?
Answer:
- If any class in Java contains multiple methods with the exact same name but with different input parameter lists, then it is known as method overloading in Java
- In other words, if 2 or more methods in a Java class have the same name with different input parameters, then it is called method overloading in Java
What is comprised of the method signature in Java for method overloading?
Answer: Method signature consists of below things (for overloading)
- method name (should be same)
- number of input parameters
- data-type of input parameters
What are the things to consider while overloading methods in Java?
Answer: When we overload methods in Java, the compiler checks 3 things
- method name (should be same)
- number of input parameters
- data-type of input parameters
The method name has to be the same, and the combination of the number of input parameters & their data type has to be different for successful compilation
Is overloading a run-time or compile-time polymorphism?
Answer: Compile-time polymorphism, as it is resolved at compile-time
Whether method overloading is a static binding or dynamic binding?
Answer: Static binding, as it is resolved during compile-time
What are the other names used to refer to method overloading?
Answer: Compile-time polymorphism or Static binding
What are the ways to overload methods in Java?
Answer: Below are the ways to overload methods in Java by changing
- Number of input parameters
- Data-type of input parameters
- Order of input parameters, if they are of different data types
Note: the return type is not valid to consider for overloading concepts
What are the restrictions on access modifiers in method signature while overloading in Java?
Answer: Access modifiers don’t affect method overloading, so overloaded methods can have the same or different access levels
Does the access modifier affect method overloading in Java?
Answer: Access modifiers don’t affect method overloading, so overloaded methods can have the same or different access levels
Is it possible to overload methods in Java just by changing the return type?
Answer: No, it is not valid to consider return type for method overloading
The class compiles successfully if we have two methods with the same name but different return types.
Answer: Compilation fails with the below error
Error: Duplicate method method_Name(input parameters) in type ClassName
Can a method be overloaded based on different return types but the same argument type?
Answer: No, compilation fails
Why is it not possible to overload methods based on the return type?
- The reason is type ambiguity
- First of all, we cannot have two methods with exactly the same input parameters. In this case, the compiler throws an error
- It is a compile-time error, as it is resolved during compile-time
- Also, it is very difficult for JVM to understand which version of overloaded methods to call
Is it possible to overload methods in Java just by changing different exceptions in the throws clause?
- No, an exception doesn’t affect method overloading, so overloaded methods can have any exception or not at all
- An exception doesn’t account for method overloading
The class compiles successfully if we have two methods with the same name and also the same/different return type but different throws exceptions?
Answer: It depends on the number and data type of input parameters
Can we overload static methods in Java?
Answer: Yes, we can overload the static method
Can we overload the main() methods in Java?
- Yes, we can overload the main() method, which is static
- But the entry point to JVM will remain the same main() method with the below signature
- Public static void main(String args[])
Can we overload constructors similar to method overloading?
Answer: Yes, constructor overloading is possible, but that is different from method overloading
Can we declare overloaded methods as final?
- Yes, the access modifier (private, default, protected, public) doesn’t affect method overloading
- Similarly, non-access modifiers like final, static, transient, synchronized, volatile, abstract, and strictfp don’t account for method overloading
Can we overload methods that differ only by static keyword?
Answer: No, compilation fails as non-access modifiers like static is not considered for method overloading
Does the class compile if we have two methods with exactly the same method signature (method name, same input parameter, and their data types) but one with a static keyword and the other non-static?
- No, compilation fails as non-access modifiers like static are not considered for method overloading
- The compiler throws an error for the Duplicate method, as shown in the below screen capture
Why is method overloading required in Java
- Suppose if we want to perform similar kinds of tasks, and their operation differs only by a number of parameters or their data types or both then method overloading is the best concept to apply
- Maintains consistency with method naming for a similar type of tasks
- Increases the readability of the program
- This helps the developer to invoke the method with the same name, but the change required arguments in the required order with their corresponding data types
- Example: java.lang.String class from java.lang package contains 9 overloaded ‘valueOf()’ methods with a different number of input parameters or their data types
Can an overloaded method override?
Answer: Yes, as far as it abides/complies with overriding rules (See overriding rules here)
What is the difference between method overloading and v/s method overriding in Java?
Answer: Refer to Method overriding v/s method overriding in Java
References: Article
