Wipro Java Developer Interview Questions with Answers (Mid-Level Role)

 Wipro Java Developer Interview Questions with Answers (Mid-Level Role)

(Glassdoor Based – May 2024)

Interview Location: Bengaluru
Interview Mode: Online
Candidate Role: Mid-Level Java Developer
Source: Based on real experience shared on Glassdoor
Review Summary: Easy and conversational. Interviewer was friendly. Focus was mainly on Java basics, internals, and real-world understanding.

Q1: What is static in public static void main(String[] args)?

A:
The static keyword lets the JVM call the method without creating an object. It indicates that the method belongs to the class, not instances.

Q2: Why does a Java program start from the main method?

A:
main() is the predefined entry point of a Java application. The JVM starts execution from there.

Q3: What are Checked and Unchecked Exceptions? With examples.

A:

• Checked Exceptions: Detected at compile time. E.g., IOException, SQLException.
• Unchecked Exceptions: Detected at runtime. E.g., NullPointerException, ArithmeticException.

Q4: What is Custom Exception Handling?

A:
Creating your own exception by extending Exception or RuntimeException.

java

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class MyException extends Exception {

    public MyException(String message) {

        super(message);

    }

}

Q5: What are Java 8 features used in projects?

A:

• Optional class
• Functional Interfaces (e.g., Predicate, Function)
• Stream API
• Lambda Expressions
• Default & Static methods in interfaces

Q6: Explain the OOPS concepts.

A:

• Abstraction
• Encapsulation
• Inheritance
• Polymorphism

Q7: Difference between Method Overloading and Overriding?

A:

• Overloading: Same method name, different parameters (compile-time).
• Overriding: Subclass redefines superclass method (runtime).

Q8: When do you use Method Overriding?

A:
To change the behavior of a method in a child class based on your business logic.

Q9: What is an Unreachable Catch Block?

A:
Occurs when a catch block will never be executed due to a broader exception already being caught before. It’s a compile-time error.

Q10: Why is String immutable in Java?

A:

• Thread safety
• String pool reuse
• Secure for class loading
• HashCode consistency

Q11: Difference between StringBuilder and StringBuffer?

A:

• StringBuilder: Not synchronized, faster.
• StringBuffer: Synchronized, thread-safe.

Q12: Components of @SpringBootApplication?

A:

• @Configuration
• @EnableAutoConfiguration
• @ComponentScan

These together make it easy to bootstrap Spring Boot apps.

Q13: What is Agile Methodology?

A:
A development process that delivers software in small, workable increments. Scrum is a popular framework.

Q14: Commonly Used Design Patterns?

A:

• Singleton
• Factory
• Strategy
• Observer
• Builder

Q15: What does the static keyword do?

A:
Defines class-level members. They’re shared across all instances of the class.

Q16: Can Static Methods be Overloaded?

A:
Yes, but they cannot be overridden. You can define multiple static methods with different parameters.

Q17: What is valueOf() used for?

A:
Converts string or primitive types to wrapper objects.

java

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Integer i = Integer.valueOf("100");

Q18: Logic-based questions asked?

A:

• Reverse a string
• Check palindrome
• Remove duplicates from array
• Project-related business logic problems