Coding Projects and Duga Heaven :)

public class localVariableExample {
	public static int foo;
	public static void main(String[] args) {
		int bar;
		System.out.println("foo : " + foo);
		System.out.println("bar : " + bar); // compile error
	}
}

Versus this:

public class localVariableExample {
	public static int foo;
	public static void main(String[] args) {
		int bar = 1;
		System.out.println("foo : " + foo);
		System.out.println("bar : " + bar); // no error
	}
}

bazola

in the first example, the variable is uninitialized

Phrancis

Is it where a variable declared inside the same method it's being called need to be explicitly initialized?

I'm just mostly wondering about why foo becomes initialized by default

Simon André Forsberg

@Phrancis foo is a field and not a local variable.

Local variables don't get automatically initialized.

Phrancis

I see. When I System.out.println("foo : " + foo); why does it return 0 if it's not a variable...?

Simon André Forsberg

I can't quote the JLS (Java Language Specification) by heart, but I know it's in there...

@Phrancis a field is a variable. Just a different kind of it.

Phrancis

6:29 PM

So what if I do this:

public class localVariableExample {
	public static int foo = 1;
	public static void main(String[] args) {
		int bar = 1;
		System.out.println("foo : " + foo);
		System.out.println("bar : " + bar);
	}
}

Simon André Forsberg

that will work, yes.

you initialize both variables to 1.

Phrancis

Does that change the nature of foo or just its value?

Simon André Forsberg

public static int foo; gets initialized by default to 0

@Phrancis just the value

Phrancis

Ok... Bit confused about what a "field" is for then, vs. a "variable"... but TFL

By all means I'll read anything else you type meanwhile :)

Simon André Forsberg

@Phrancis it's about scope. Local variables are only available inside one method. Fields is available in the entire class (if it's not private, it's even available in other classes)

public class localVariableExample {
	public static int foo;
	public static void main(String[] args) {
		System.out.println("foo : " + foo);
	}

	private static void otherMethod() {
		System.out.println("otherMethod foo : " + foo);
	}
}

^^ this will work fine

skiwi

6:36 PM

help

How do I name my character in ESO

skiwi is already taken!

Simon André Forsberg

public class localVariableExample {
	public static int foo;
	public static void main(String[] args) {
		int bar = 1;
		System.out.println("foo : " + foo);
		System.out.println("bar : " + bar);
		otherMethod();
	}
	private static void otherMethod() {
		System.out.println("foo : " + foo);
		System.out.println("bar : " + bar); // compiler error
	}
}

^^ in otherMethod(), "bar" is not available, because it's a local variable in main

skiwi

Any suggestions for a name, anyone?

Simon André Forsberg

unfortunately not

Speaking of name, @Phrancis, public class LocalVariableExample

skiwi

I'm thinking MrSkiwi ... but it sounds decent, but not good

Marc-Andre

6:56 PM

9

Q: Java: Why am I required to initialize a primitive local variable?

public class Foo { public static void main(String[] args) { float f; System.out.println(f); } } The print statement causes the following compile-time error, The local variable f may not have been initialized If primitives in Java already have a default value (float...

SO to the rescue

Simon André Forsberg

What, no JLS?

Phrancis

@skiwi Maybe FrankSkiwi ?

@SimonAndréForsberg That makes a lot of sense! Learning things today :D

Of all data types, why is only String capitalized?

Marc-Andre

@SimonAndréForsberg docs.oracle.com/javase/specs/jls/se5.0/html/…

@Phrancis String is a class and not a primitive type

Phrancis

Is that also my it needs quotes? Is it because it's passing an "argument" to that String class?

Simon André Forsberg

7:12 PM

@Phrancis String is a bit of a special class in Java. You can use the + operator on it and stuff. The fact that it needs quotes is just that you can give it a value by using the quotes. For example, String name = "Phrancis";

it is the only class in Java that can be treated in a special way

Phrancis

Ok. I'm sure it will make more sense later as I learn more about classes and objects :)

I'd be curious to see some code from Cardshifter with these simple basics concepts

Simon André Forsberg

Use the source, Luke.

Phrancis

lol

Yeah looking at some stuff in PhrancisGame

Marc-Andre

@SimonAndréForsberg It's not the only one, you have Integer, Float, Boolean and all the Object class of the primitive type.

Phrancis

7:34 PM

/** Comment
* Are comments like these still used in Java?
*/

(working from an older tutorial, trying not to learn bad habits along the way ;)

Simon André Forsberg

@Marc-Andre good point

skiwi

@Phrancis Considered, but I disliked it, I think I'll roll with MrSkiwi!

Simon André Forsberg

@Phrancis /** are Javadoc. /* are comments.

Marc-Andre

^^ that

Phrancis

7:48 PM

So I wrote this @SimonAndréForsberg :)

public class HelloWorld
{
	String output = "";
	static HelloWorld helloObj;

	public HelloWorld()
	{
		output = "Hello World";
	}

	public String PrintMessage()
	{
		return output;
	}

	public static void main (String args[]) {
		helloObj = new HelloWorld();
		System.out.println(helloObj.PrintMessage());
	}
}

Simon André Forsberg

So, quick code review:

static HelloWorld helloObj; should be a local object in the main method

String output = ""; does not need to be initialized when it's declared. You can make that private final String output; and initialize in constructor (it can also be initialized where it's declared, of course)

public String PrintMessage() should be named printMessage() according to camelCasing. It doesn't actually print something though so getMessage() would be a better name.

Now, don't listen to my complaints about your code. You write Java, you're making it do the job, awesome!

Phrancis

lol. Surprised you haven't said anything about the indentation, I was kind of wanting to gauge your reaction ;-)

Simon André Forsberg

Indentation is perfect

but you're using C#-style braces and not Java-style ;)

Phrancis

Now, which part of this thing would be the "constructor"? Haven't read about that

Simon André Forsberg

public HelloWorld()

a method that has the same name as the class itself, but no return type (not even void), is a constructor.

Phrancis

7:55 PM

So is that constructing an instance of the HelloWorld() class, with a value of "Hello World" basically?

Simon André Forsberg

@Phrancis yes.

Phrancis

Or is it rather, an instance of HelloWorld() with an output property of value "Hello World" ?

Simon André Forsberg

that's more accurate, yes.

Duga

[Zomis/Connecting-Blocks] Zomis added label desktop to issue #18: Back to menu

Phrancis

public class HelloWorld {
	private final String output;

	public HelloWorld() {
		output = "Hello World";
	}

	public String PrintMessage() {
		return output;
	}

	public static void main (String args[]) {
		static HelloWorld helloObj; 	// illegal start of expression
		helloObj = new HelloWorld();
		System.out.println(helloObj.PrintMessage());
	}
}

Simon André Forsberg

7:58 PM

remove static when it's a local variable

Marc-Andre

PrintMessage() -- >printMessage()

Simon André Forsberg

7 mins ago, by Simon André Forsberg

public String PrintMessage() should be named printMessage() according to camelCasing. It doesn't actually print something though so getMessage() would be a better name.

Phrancis

Yeah I wanted to make sure it compiled before I started renaming things

Simon André Forsberg

good thinking ^^

Phrancis

Still not too confident about what static and final are for. I think I understand private/public OK

skiwi

8:01 PM

@Phrancis Don't make your privates public!

Phrancis

Well, here is the modified code, looks more understandable, thanks for the micro-review :)

public class HelloWorld {
	private final String output;

	public HelloWorld() {
		output = "Hello World";
	}

	public String getMessage() {
		return output;
	}

	public static void main (String args[]) {
		HelloWorld helloObj; 	// illegal start of expression
		helloObj = new HelloWorld();
		System.out.println(helloObj.getMessage());
	}
}

Marc-Andre

@Phrancis A quick definition : final -> Will not change. static -> Will be "attached" to the class

So one is about if it can be modified and one is to define if it's "attached" to the class or an instance of the class.

skiwi

@Marc-Andre static, there is only one such instance for every class

Phrancis

So they are not mutually exclusive... like public static final String foo; would mean it cannot be changed (after initialized/set?) but can be attached?

Marc-Andre

@skiwi It's a better definition thanks

@Phrancis Attached is not a good word (that is why I've used quotes) but yeah it's the spirit of the thing. Final static means : the variable is accessible to all the instance of the class and is guarantee to not be modified (there are some exceptions, but those are not worth to be explained at the moment)

Because modifying a final variable is normally an insane thing to do.

3

Phrancis

8:07 PM

OK that makes more sense

So once the constructor HelloWorld() sets the output property to "whatever" would declaring output as final throw a compiler flag if it was modified again?

Guess it'd be easy to find out

> Compilation Errors Detected

Line: 12
constructor HelloWorld() is already defined in class HelloWorld

Marc-Andre

Compiler time only happens at compile time. So If you have `final String finalString = "Should not change";
finalString = "Error"; //<-- this will throw a compile error`

@Phrancis You've re-declared the constructor, you just need to try to re-assign a value to the variable and it should break,

Phrancis

> Compilation Errors Detected

Line: 9
cannot assign a value to final variable output

Marc-Andre

Good so you see, you can't assign more than once when you use final.

skiwi

iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

Marc-Andre

@skiwi ??

skiwi

8:23 PM

whoops

was using the wrong mouse profile and pressed a button

Duga

[Zomis/Connecting-Blocks] Zomis pushed commit 4df32cda to master

> created README.md

Simon André Forsberg

@skiwi like my keyboard macro? git log --branches --graph --decorate --oneline

git log --branches --graph --decorate --oneline

I love that Macro :)

skiwi

8:36 PM

@SimonAndréForsberg You made a macro for that? That's awesome

Simon André Forsberg

of course I did!

skiwi

I just set up a mouse profile so I can use (I, J, M) for (Inventory, Quests, Map) on my mouse in The Elder Scrolls Online... No more need to get my hands of my mouse!

Marc-Andre

@skiwi I used my left hand for this ! :P

3

bazola

@skiwi is it fun so far?

skiwi

@Marc-Andre That's... hard, I'd say ;)

@bazola So far it's good! Just spent 1 hour though

Marc-Andre

8:39 PM

@skiwi Why ? (I guess I'm missing some information here)

skiwi

@Marc-Andre You're usually walking around with WASD using your left hand

Marc-Andre

@skiwi That only 4 finger at most, you still have your thumbs normally. But that is the way I'm used to.

Not trying to say it's not helpful to have I J M on the mouse!

I'm just used with my Razor Naga to have a bunch of additional spells accessible on the mouse instead of utility like quest and map

skiwi

@Marc-Andre The thumb is needed for Alt :p

@Marc-Andre Do you play ESO as well?

Marc-Andre

@skiwi Alt ? And no I'm a Wow player (with a second lvl 100 on the way)

skiwi

@Marc-Andre You need to use Alt a lot, so that's where you thumb is

I don't think ESO has (many) additional spells, it's similar to GW2 in that respect

Marc-Andre

8:48 PM

Then it's a better option to put common utility then! But I'm quick at using my keyboard and do much Pvp so I fell comfortable to access those key with my left hand.

Simon André Forsberg

I need a naming suggestion, say that I want to extract my ECS code to it's own library, what should be the name?

skiwi

@SimonAndréForsberg ecs

Marc-Andre

ECS ?

Phrancis

Whew, just had to defuse an escalation. Fun stuff.

Simon André Forsberg

@Phrancis what escalation?

@skiwi @Marc-Andre "ECS" feels too common. It is ECS code, but naming it purely "ECS" is not a good idea, as there are other ECS frameworks

Phrancis

8:54 PM

Work related stuff, nothing very interesting. Insurance stuff, ya know.

Did take up almost an hour of research though.

bazola

All the ECS frameworks seem to come up with silly names

Simon André Forsberg

@bazola I also want a silly name!

Don't force me to use this

bazola

that is a tall order! at least to avoid using something that has been taken

skiwi

@SimonAndréForsberg Olufunmilayo

Marc-Andre

@SimonAndréForsberg What this library will be used for ? Is it your service layer, api layer or anything else ? {project.name}-api/service could do it

Simon André Forsberg

8:59 PM

@Marc-Andre I don't think it's either. I guess you could call it a framework-layer.

group name will be net.zomis.

Marc-Andre

Is it like a persistent layer ? I don't quite understand what it's suppose to do

Simon André Forsberg

@Marc-Andre How much do you know about the Entity Component System approach to games?

I guess you could call it an abstraction layer.

Marc-Andre

@SimonAndréForsberg Well nothing actually. Never worked on a game. So I can't really help to name things I don't understand the concept. But if it's an abstraction layer or something like a framework then give it a simple name that stand out. Some greek god that did a "similar" job.

Simon André Forsberg

> Some greek god that did a "similar" job.

Decima, perhaps. With perhaps a little reference to Person of Interest :)

It's Roman though, not Greek :/

Marc-Andre

9:16 PM

@SimonAndréForsberg Well it does not matter much ;). Most of Roman deities (plural of deity) are taken from other mythologies so.

Phrancis

in The 2nd Monitor, 1 min ago, by Simon André Forsberg

Perhaps Lachesis, the Greek equivalent.

Simon André Forsberg

I like the name Lachesis though. Although the Goddess is totally irrelevant to what the framework actually does.

Now for a more important question: Java 6 or Java 8...

android :(

Marc-Andre

Java 8 and TTQW

Simon André Forsberg

Well, I can always make it Java 8 now and backport later if I need it.

for what I need right now, I only need Java 8.

Perhaps 'Lachecs' / LachECS

Naaa, Lachesis

Phrancis

"esis" almost sounds out ECS, I think it will be cool

Simon André Forsberg

9:24 PM

net.zomis.lachesis it is!

3

Phrancis

When making a constructor, what is the use of the () at the end of the name?

Simon André Forsberg

@Phrancis it is for parameters, just like calling other methods

public class HelloWorld {
	private final String output;

	public HelloWorld(String name) {
		output = "Hello World, " + name;
	}

	public String getMessage() {
		return output;
	}

	public static void main (String args[]) {
		HelloWorld helloObj; 	// illegal start of expression
		helloObj = new HelloWorld();
		System.out.println(helloObj.getMessage());
	}
}

Make that work ^^

(yes, I copied your code)

Phrancis

Hmm, a bit stumped... I got this far:

public class HelloWorld {
	private final String output;
	public HelloWorld(String name) {
		output = "Hello World, " + name;
		name = "Simon";
	}
	public String getMessage() {
		return output;
	}
	public static void main (String args[]) {
		HelloWorld() helloObj; 	// not a statement
		helloObj = new HelloWorld();
		System.out.println(helloObj.getMessage());
	}
}

> Compilation Errors Detected

Line: 13
';' expected

Line: 14
';' expected

Line: 14
not a statement

Simon André Forsberg

HelloWorld() helloObj;

that's the declaration, you shouldn't use paranthesis when declaring a variable

helloObj = new HelloWorld();

^^ that is where you need to make a change

new HelloWorld() tires to call a constructor without a parameter

but as the code is public HelloWorld(String name) it now requires a parameter

Phrancis

9:42 PM

Hmm, ok. Not quite there yet

	public static void main (String args[]) {	// ';' expected
		HelloWorld helloObj;
		helloObj = new HelloWorld(String name);	// illegal start
		System.out.println(helloObj.getMessage());
	}

Simon André Forsberg

new HelloWorld(String name)

instead of String name you should here specify the actual name that the constructor should use

In the constructor, you have name = "Simon"; but that code doesn't really have any effect because it is called at the end of the constructor and the variable is only local to the constructor.

Phrancis

OK. Only one more thing, no idea why but I'm guessing... syntax error somewhere?

	public static void main (String args[]) {	// ';' expected
		HelloWorld helloObj;
		helloObj = new HelloWorld("Simon");
		System.out.println(helloObj.getMessage());
	}
}

try String[] args

Same thing

post all the code

9:50 PM

public class HelloWorld {
	private final String output;
	public HelloWorld(String name) {
		output = "Hello World, " + name;
	}
	public String getMessage() {
		return output;
	}
	public static void main (String[] args) {	// ';' expected
		HelloWorld helloObj;
		helloObj = new HelloWorld("Simon");
		System.out.println(helloObj.getMessage());
	}
}

Simon André Forsberg

works on my machine

blaming Netbeans

Phrancis

I'm actually using browxy.com

But you're probably right

Well, lots of new knowledge today! If only my colleagues bothered to try to learn something when we're slow, instead of reading novels... :)

in The 2nd Monitor, 19 mins ago, by Malachi

if they only knew what was good for them

I think I might pursue this Java escapade. I hear Java developers are in high demand (good ones, that is).

Duga

10:07 PM

Ping: Practicality beats purity.

4

[Zomis/Lachesis] Zomis created branch master

[Zomis/Lachesis] Zomis pushed commit 40008333 to master

> initial commit

[Zomis/Lachesis] Zomis pushed commit 3817c592 to master

> added core classes, players and events

Phrancis

10:30 PM

@SimonAndréForsberg Does this also work on your machine?

public class Foo {
		// What would be the difference here?
		// this
		int i1 = 1;
		// versus
		Integer i2 = new Integer("1");
	public static void main(String[] args) {	// ';' expected
		System.out.println("i1 : " + i1);
		System.out.println("i2 : " + i2);
	}
}

Simon André Forsberg

10:41 PM

class Foo {
	// What would be the difference here?
	// this
	int i1 = 1;
	// versus
	Integer i2 = new Integer("1");
	public static void main(String[] args) {
		System.out.println("i1 : " + i1); // Cannot make a static reference to the non-static field i1
		System.out.println("i2 : " + i2); // Cannot make a static reference to the non-static field i1
	}
}

@Phrancis it's about primitive variables and non-primitives. It's.... complicated. But I'd recommend that whenever possible, stick to primitives (int)

Phrancis

Hm. Interesting. Neither of those came up on that compile site

Simon André Forsberg

for the record, Integer i2 = 1; also works.

Phrancis

Ok. Will do

Simon André Forsberg

I'd recommend ideone.com

Phrancis

OK I'll give that one a whirl. Are imports needed at all, for real simple stuff like I'm doing?

Simon André Forsberg

10:47 PM