What is an object in java

What is an object in java: In Java, an object is an instance of a class that encapsulates data and behavior. A class is a blueprint or a template for creating objects, and an object is created by instantiating a class. Once an object is created, it has its own state and behavior, which is defined by the class.

What is an object in java?

Objects in Java have the following characteristics:

1. State: Every object has a state, which is defined by the values of its instance variables.
2. Behavior: Every object has behavior, which is defined by its methods.
3. Identity: Every object has a unique identity, which distinguishes it from all other objects.

For example, let’s say we have a class called “Car” that has instance variables such as “make”, “model”, and “year” as well as methods like “startEngine” and “stopEngine”. When we create an object of the “Car” class, we can set its state by assigning values to its instance variables, and we can call its methods to perform actions such as starting or stopping the engine.

Here’s an example code snippet that creates an object of the “Car” class:

Car myCar = new Car();
myCar.make = "Toyota";
myCar.model = "Camry";
myCar.year = 2021;
myCar.startEngine();

In this code, we create a new object of the “Car” class using the “new” keyword, and then set its state by assigning values to its instance variables. Finally, we call the “startEngine” method on the object to start the car’s engine.

Core Java More Article –

• What is local variable in java with example
• What is a non-static variable in java
• What is a local variable in java
• What is Method In Java With Example

Top 10 interview questions core java

Sure, here are 10 commonly asked interview questions on core Java:

1. What is the difference between a class and an object in Java?
2. What is the difference between an abstract class and an interface in Java?
3. What is a constructor in Java? How is it different from a method?
4. What is the difference between checked and unchecked exceptions in Java?
5. What is the difference between final, finally, and finalize in Java?
6. What is the purpose of the “static” keyword in Java?
7. What is the difference between “==” and “.equals()” in Java?
8. What is the difference between an ArrayList and a LinkedList in Java?
9. What is the difference between a stack and a queue in Java?
10. What is the purpose of the “synchronized” keyword in Java?

These questions cover a range of topics in Java, including object-oriented programming, exception handling, keywords and data structures. It’s important to note that interviewers may ask follow-up questions to these basic questions to test your deeper understanding of the concepts.