a question about the name of Java commands

[chriskin]

certain commands in Java seem too big for no reason

for example , is there any reason why "System.out.print" is not called just "print"?
:popcorn:

(just started programming on first year at University , the question might be too stupid)

[dearingj]

for example , is there any reason why "System.out.print" is not called just "print"?

I wouldn't really call it a "command"; it's a function. A function which is part of the out object, which is part of the System object. You could, if I'm not mistaken (haven't tried this) create your own object of the same type as out and have your object output to the console, so then you'd only have to call something like


myOut.println();

Or, probably a simpler thing to do would be to create a print() function in your program, which just calls System.out.println() itself, so you'd only have to call print().

[RiceMonster]

It's not really a command as such; it's a function. A function which is part of the out object, which is part of the System object.

I think the word you're looking for is method, not function.

[kavon89]

certain commands in Java seem too big for no reason

for example , is there any reason why "System.out.print" is not called just "print"?

When it comes down to it, everything in Java is something called a class. System is the class that was designed for things such as printing to a terminal.

Also, there is no such thing as a command in Java. In that statement, what you're actually doing is calling the static method "print()" of the static PrintStream (http://java.sun.com/javase/6/docs/api/java/io/PrintStream.html) object "out" within the class System (http://java.sun.com/javase/6/docs/api/java/lang/System.html).

[dearingj]

I think the word you're looking for is method, not function.

Is there a difference? I was always taught that they're two words for the same thing.
http://en.wikipedia.org/wiki/Function_%28computer_science%29

[RiceMonster]

Is there a difference? I was always taught that they're two words for the same thing.
http://en.wikipedia.org/wiki/Function_%28computer_science%29

Similar, but not the same. A method is more or less a function within/belonging to a class. A function is independent, not contained within anything.

This would be a function (in C):

int addNums(int x, int y) {
return x + y;
}


This would be a method (in C++):

class nums {
private:
int x, y;
public:
int addNums (int x, int y) {
return x + y;
}
}


Get what I mean? Sorry for using C/++ rather than Java, I don't really know Java.

[dearingj]

Similar, but not the same. A method is more or less a function within/belonging to a class. A function is independent, not contained within anything.

<snip>

Get what I mean? Sorry for using C/++ rather than Java, I don't really know Java.

I see :)
I do most of my coding in C++, so no problems understanding your code.

[chriskin]

I wouldn't really call it a "command"; it's a function. A function which is part of the out object, which is part of the System object. You could, if I'm not mistaken (haven't tried this) create your own object of the same type as out and have your object output to the console, so then you'd only have to call something like


myOut.println();

Or, probably a simpler thing to do would be to create a print() function in your program, which just calls System.out.println() itself, so you'd only have to call print().

what i asked, or at least wanted to ask, was : would there be any problem if the System.out. part was not asked? is it needed or is it just showing that i am using System?

sorry of using the word "command" since everyone commented , it's just that they taught it to us as "entoli" which means command on greek. probably they used the word closer to us from high-school's "programming language"

[kavon89]

what i asked, or at least wanted to ask, was : would there be any problem if the System.out. part was not asked? is it needed or is it just showing that i am using System?


Yes, gigantic problems. Your question is relatively stupid and all you need to know for now is that System.out.print() allows you to print text to a terminal.

[chriskin]

Yes, gigantic problems. Your question is relatively stupid and all you need to know for now is that System.out.print() allows you to print text to a terminal.

i know that my knowledge of Java is too small to even call it basic, but i have seen questions way more stupid than the one i asked.

can you tell me what difference the system.out. part makes and why it is needed?

[kavon89]

A method is more or less a function within/belonging to a class. A function is independent, not contained within anything.

Yep, and it's impossible to define a function that does not belong to a class in Java.

[kavon89]

can you tell me what difference the system.out. part makes and why it is needed?

Ugh, ok here goes:

System is an object. It always exists every time you run a Java program and allows you to do things which are related to the computer your program runs on, like asking what time it is.

It also allows you to output text to the computer system's terminal/command line. There is another object that System owns which is called out. That object is the compuer system's command line. It has a method [you can think of a method like a command] called print.

In order to access print, you must first go to System, then go to out. The notation to print to the terminal: Hello World would be as follows:


System.out.print("Hello World");

If an object called Chef had a "command" called cookDinner, it would look like this:


Chef.cookDinner();

[mehaga]

Your question is relatively stupid

Wow


System is an object...
Now, that's stupid.

[kavon89]

Now, that's stupid.


public final class System extends Object

Every class in Java extends Object and an instance of a class is an object. If chriskin were to be told that System is an object, it isn't completely wrong yet understandable.

[hobo14]

Wow

Now, that's stupid.
?

[Hyporeal]

If you're a fan of brevity, you could use a static import:


import static System.out;

Then you can write to standard output with:


out.println("Hello");

This, however, is incorrect:


println("Hello"); // INCORRECT

You need the "out" because otherwise no one knows what you're writing to. You could have multiple print streams open (files, standard output, standard error, input pipes to other programs, string buffers, etc.) so you need to specify "out" to let the runtime know what you're printing to.

However, I would recommend that you keep the full "System.out.println" because it is so common that people immediately understand what it does. It improves the readability of your code.

[forrestcupp]

Yes, gigantic problems. Your question is relatively stupid and all you need to know for now is that System.out.print() allows you to print text to a terminal.

That's a relatively stupid response. It's not a stupid question.

I don't know Java, but in C++, you can use a

using namespace std;so that you don't have to put an "std" on the front of everything in that namespace. If that ability is built into C++, there is a reason for it, and it's not a stupid question.

I just don't know if Java has an equivalent. Someday, I'll take the time to learn Java.

Edit:
Hyporeal already beat me with the answer.

[mehaga]

?

I just wanted to give 'that's stupid' back to him. See his response and you'll know why I think that was 'stupid'.

[kavon89]

I just wanted to give 'that's stupid' back to him. See his response and you'll know why I think that was 'stupid'.

What's stupid is giving a very complicated explanation to a beginner.

[chriskin]

You need the "out" because otherwise no one knows what you're writing to. You could have multiple print streams open (files, standard output, standard error, input pipes to other programs, string buffers, etc.) so you need to specify "out" to let the runtime know what you're printing to.


thanks :)


What's stupid is giving a very complicated explanation to a beginner.

well, if you didn't want to give the explanation, why bother answering? being a beginner doesn't make somebody stupid so that he can't understand something if you explain it in a way that it doesn't require knowledge of programming :)
the way i see it, everybody was a beginner at programming before they started learning (obviously...)

[mehaga]

What's stupid is giving a very complicated explanation to a beginner.

No need to argue. I believe this forum is Ubuntu's strongest feature. One of the reasons it is so good is that it is noob-friendly most of the time. Your comment was not noob-friendly... Anyway, let's leave 'stupid' out of our future posts, ok?
No pipe of peace smiley, so I'll offer: :popcorn: