object definition in oops

Question

how will you define an object?

Answer 1

Object in programming language is just like an object in a real world. Think of "Object" in code as a "thing" when you are reading a book. "Object"/"thing" both have two things, properties and things they can do.

e.g book What property does book have? books have colors, weight, number of pages, etc.

e.g person. what property does a person have? tallness, weight, etc.. and what can they do? they can do talking, walking, writing, etc.

Answer 2

You define an object using what is typically called a class (in any OO language I've used anyways). The class is a blueprint that describes the type of data and behavior an instance (or object) of the class would have. Here is an example of what that might look like in Java:

public class Greeter {
  private String greeting;

  Greeter(String aGreeting) {
    this.greeting = aGreeting;
  }

  public void greet() {
    System.out.println(greeting);
  }

}

When you run your program, you instantiate (or create) an object by providing the class that you want to create an instance of. You can then assign it to a variable and call methods (or functions) on it. In Java, it looks like this:

Greeter myGreeter = new Greeter("Hello, World!");
myGreeter.greet();

If you just want to understand the basics of Object Orientation, I would highly recommend a book called The Object-Oriented Thought Process by Matt Weisfeld.

Answer 3

An object is something you (or routine you call) need to do new to create.