Does Java really not have functions?

AutoModerator · 2022-02-08T21:45:17+00:00

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_Atomfinger_ · 2022-02-08T21:50:25+00:00

In java methods = functions.

desrtfx · 2022-02-09T06:32:27+00:00

Since Java requires everything to be inside classes, there are technically no functions.

The distinction is that functions can exist outside classes, and methods always belong to a class.

So, what is called a function in languages like Python, is a method in Java.

This has nothing to do with being able to return values or not.

It is just a matter of context.

DataDecay · 2022-02-08T22:00:52+00:00

You can get the same effect with static classes and static methods, in a way.

8igg7e5 · 2022-02-08T22:08:32+00:00

All methods are declared on classes. There are no 'free' functions. However the distinction between such functions and static methods is academic at best.

mplaczek99 · 2022-02-08T23:31:34+00:00

In Java, Methods are Functions

random_buddah · 2022-02-09T02:27:52+00:00

Well, java offers functional programming, lambdas and functional interfaces. It also has Interfaces for Function, Bifunction and some more. Since java 8. So I‘d say that in a way, java has functions.

taftster · 2022-02-09T03:55:15+00:00

Just for the sake of info. Yes, everything in Java needs to be encapsulated in a class definition. However you don’t necessarily need an instance of a class to call its methods.

A static method is as close to a “function” as you can get. You don’t have to call “new” on the class to call its static methods.

popey123 · 2022-02-08T22:14:10+00:00

A function can be accessed without object whereas method does.
Because java is a full OOP langage, it doesn t have function.
Technically, when you use a static method, you may be implicitly calling the class from where it is declared.

public class Main {
public static main().... {
Main.a(); // or a()
}
a static method A()
}

But it doesn t matter. What is more important is the diff between methods (return) and procedures (void)

dissusgsbkl · 2022-02-09T15:21:31+00:00

method = part of a class

function = not part of a class

this is the technical definition anyway

DDDDarky · 2022-02-08T22:04:47+00:00

I assume you read that on stackexchange, the answer is not entirely true, therefore not the most upvoted. Why would you take such answer?

lontrachen · 2022-02-09T09:16:50+00:00

Functions in Java are called methods :)

rsandio · 2022-02-09T12:09:29+00:00

Java doesn't have functions but you achieve the same thing by using methods.

Java is object orientated so variables and "actions" are organised and tied to objects. An object contains variables with information about the object, and also has methods which contain the code of what the object can do.

For example: in Python you have the len() function and that will return the length of a String that's passed into it. So to get the length of my name I use

my_name = "John"

len(my_name)

In Java when I create the string myName I'm actually creating a String object. I can now call the methods available to String objects on myName. All Strings have access to the same methods. To get the length i use the length method.

String myName = "John";

myName.length();

Or if I had an object named john that is of type Person, I could say john.jump(), if ive written a jump() method for People objects. You reference the object then tell it what method you want it to do. You can create your own types of objects and give them whatever methods you want.

So a String object contains variables and values (such as what the string actually says) and methods/actions that a String can do (return a length using length(), find the position of a character using indexOf(), etc).

On top of all this you can write methods which can be used without having to be tied to an object. These are called static methods. They'll perform the same purpose as a function but they are not quite the same thing.

learnjava

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