Question

I have been hearing about how C is a non-object-oriented language and how java is an object-oriented language. I was wondering what the difference was?

Answer 1

Wow, a lot of big OOP terms being thrown around to this guy. Being one who started in procedural programming and is now mostly doing OOP, this is conceptually how I think of the difference (without all the big terms):

In C, you have things called structs that can hold state. They kind of seem like objects, for example you could have a struct called Car and create instances of Cars and set its make, model, and color fields. However, you cannot tell the Car struct instances to do anything. Instead, if you want to wash your car, you have to pass the car instance to some external function like this:

WashMyCar(myCar);

OOP languages use a different concept from structs called Classes, and objects are instances of those classes. Forget about those big words inheritance and polymorphism for now (those are more advanced topics for once you kind of get Classes). Just think of the example of a car. In Java, for example, you could define a class called Car as such:

public class Car {
  String make;
  String model;
  String color;
}

Then, you make an instance of a car like so:

Car myCar = new Car();
myCar.make = "Honda";
myCar.model = "Accord";
myCar.color = "Black";

This is real similar to a struct. Now, what makes OOP different is that you can expand the Class definition to define class methods – which are similar to functions in procedural except that they always operate on an object. So, let’s add the wash method:

public class Car {
  String make;
  String model;
  String color;
  String condition;
  void washMe() {
    this.condition = "clean";
  }
  void goOffroad() {
    this.condition = "dirty";
  }
}

Now you can do this:

Car myCar = new Car();
myCar.make = "Honda";
myCar.model = "Accord";
myCar.color = "Black";

myCar.goOffroad();
System.out.println(myCar.condition); // dirty
myCar.washMe();
System.out.println(myCar.condition); // clean

Hopefully this example helps. There is, of course, much more to OOP (and procedural) than this simple example. But the core difference is in having classes of objects that “own” their own methods.