Q1.
What is Java?
Difficulty: easy
Q2.
What are the main features of Java?
Difficulty: easy
Q3.
What is JVM?
Difficulty: easy
Q4.
What is JRE?
Difficulty: easy
Q5.
What is JDK?
Difficulty: easy
Q6.
What is the difference between JDK, JRE, and JVM?
Difficulty: easy
Q7.
What is Object-Oriented Programming (OOP)?
Difficulty: easy
Q8.
What are the four pillars of OOP?
Difficulty: easy
Q9.
What is a class in Java?
Difficulty: easy
Q10.
What is an object in Java?
Difficulty: easy
Q11.
What is the difference between a class and an object?
Difficulty: easy
Q12.
What is inheritance in Java?
Difficulty: easy
Q13.
What is polymorphism in Java?
Difficulty: easy
Q14.
What is encapsulation in Java?
Difficulty: easy
Q15.
What is abstraction in Java?
Difficulty: easy
Q16.
What is the difference between an abstract class and an interface?
Difficulty: medium
Q17.
What is method overloading?
Difficulty: easy
Q18.
What is method overriding?
Difficulty: easy
Q19.
What is a constructor?
Difficulty: easy
Q20.
What is the difference between a default constructor and a parameterized constructor?
Difficulty: easy
Q21.
What is the 'this' keyword?
Difficulty: easy
Q22.
What is the 'super' keyword?
Difficulty: easy
Q23.
What are access modifiers in Java?
Difficulty: easy
Q24.
What is the difference between public, private, protected, and default access modifiers?
Difficulty: easy
Q25.
What is a static variable and static method?
Difficulty: easy
Q26.
What is the final keyword in Java?
Difficulty: easy
Q27.
What is an exception in Java?
Difficulty: easy
Q28.
What is the difference between checked and unchecked exceptions?
Difficulty: medium
Q29.
What are try, catch, finally, throw, and throws?
Difficulty: easy
Q30.
What is the difference between == and equals()?
Difficulty: medium
Q31.
What is a String in Java?
Difficulty: easy
Q32.
What is the difference between String, StringBuilder, and StringBuffer?
Difficulty: medium
Q33.
What is an Array in Java?
Difficulty: easy
Q34.
What is a Collection Framework?
Difficulty: easy
Q35.
What is the difference between List, Set, and Map?
Difficulty: medium
Q36.
What is ArrayList?
Difficulty: easy
Q37.
What is LinkedList?
Difficulty: easy
Q38.
What is HashMap?
Difficulty: easy
Q39.
What is HashSet?
Difficulty: easy
Q40.
What is the difference between HashMap and Hashtable?
Difficulty: medium
Q41.
What is multithreading in Java?
Difficulty: medium
Q42.
What is the difference between Thread and Runnable?
Difficulty: medium
Q43.
What is synchronization in Java?
Difficulty: medium
Q44.
What is Java 8?
Difficulty: easy
Q45.
What are Lambda Expressions in Java?
Difficulty: medium
Q46.
What is the Stream API?
Difficulty: medium
Q47.
What is Optional in Java 8?
Difficulty: medium
Q48.
What is JDBC?
Difficulty: easy
Q49.
How do you connect Java to a MySQL database?
Difficulty: medium
Q50.
What is Spring Boot and why is it used?
Difficulty: medium