Java R&D interview questions

1. What is the difference between JDK, JRE, and JVM? JDK: Java Development Kit – tools to develop Java apps (includes JRE + compilers). JRE: Java Runtime Environment – runs Java applications (includes JVM + libraries). JVM: Java Virtual Machine – executes Java bytecode. --- 2. What are the main OOP principles in Java? Encapsulation: Wrapping data using classes. Inheritance: Acquiring properties from a parent class. Polymorphism: Same method, different behavior. Abstraction: Hiding internal details and showing functionality. --- 3. What is the difference between == and .equals()? == checks reference (memory address). .equals() checks content/value. --- 4. What is a constructor? A constructor is a special method used to initialize objects. It has the same name as the class and no return type. --- 5. What is method overloading and overriding? Overloading: Same method name, different parameters (within the same class). Overriding: Subclass redefines a

I think this company is super confused about the products and solutions offered by their own company. During the 1st round of interview they mentioned that they are hiring for someone who has enterprise software sales knowledge and in the 2nd round they confuse stating that they are looking for someone with hiring skills in US market. It's like comparing apples and oranges. Where is enterprise softwares and hiring and recruitment outsourcing business. Basically seems like a company that lacks vision.