r/learnjava • u/jadu2115 • 12d ago

Java Beginners: What Is an Object Actually?

I'm a Java learner and I've been learning Java for the past few months, but I still don't truly understand what an object actually is.

I've watched several YouTube videos and used AI tools to understand it, but I keep getting the same explanation: "An object is nothing but data + code."

I understand the definition, but I still can't visualize or feel what an object actually is when I'm writing Java code.

Could someone explain it in a simple, practical way, preferably with a real world analogy and a small Java example?

I feel like I'm missing one fundamental concept here. Any explanation would be really helpful. Thanks!

3 Upvotes

55% Upvoted

43 comments sorted by

View all comments

2

u/birdspider 12d ago

Could someone explain it in a simple, practical way

think of individual cars. everyone has a car (thats the object). The individual car is in some way like any other car.

When someone says "a car" he does not mean a specific one - but all of them, that's the "class".

but data + code.

cars have "code": open-window, accelerate, enable-warning-light

but they hold individual "data": color, current-speed, number-of-broken-lights, window-open-speed

hence, in an abstract way (i.e. java), one could model the "idea of a car" as a "class" and the representation of that idea / the actual thing as an (realized) "instance" of that idea.

Be aware that these are just mental or programming-language specific models to help you (or the compiler) to reason about problems.

Your CPU never sees anything like a class, object or type.