java difference between system.out.println() and println()

Question

I was wondering if there was a difference between these two e.g.

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

and

println("Hello World");

I know they print the same thing, but is there anything different? (I'm new to java, so I don't know so far)

In other words, does the "System.out" change anything?

If looking for print and prinln , println() will print an end-of-line character, while print() will not — Naga Sai A, Jun 17 '16 at 01:19
Please show a complete small program example, complete with import statements, since without this information your question doesn't quite make sense. — Hovercraft Full Of Eels, Jun 17 '16 at 01:35

score 3 · Accepted Answer · answered Jun 17 '16 at 02:10

Yes, there is a difference, because they are not calling the same method.

Assuming the second statement actually compile, it means that the println("Hello World") call is for a method that is either:

defined in your class
inherited from a super class
a default method inherited from an interface (Java 8+)
statically imported¹

Now, the local/inherited/imported println(String s) method could just have been implemented to call System.out.println(s), which would make it behave the same as the direct call to System.out.println(s), but that's different.

^{1) Since you cannot statically import java.lang.System.out.println() (it is not a static method), it would have to be statically imported from some other class.}

Eugene S · Answer 2 · 2016-06-17T02:05:33.763

2

You might have a local method called println or a static import. So:

private void println(String str) {
    //
}

or

import static java.lang.System.out;

but then it'd have to be:

out.println("bla bla");

If you are using an IDE, try to open its declaration (F3 in Eclipse) and see where it takes you.

edited Jun 17 '16 at 02:05

answered Jun 17 '16 at 01:18

Eugene S

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Sorry, i mean the function println() – Randy Huang Jun 17 '16 at 01:18
1

@RandyHuang those are methods, java prefers to call them method. – Bálint Jun 17 '16 at 01:39
If you static import `System.out`, you'd have to write `out.println()`, so that's obviously not what's going on. As for the local method, in order for `println("Hello World")` to work, the method would have to take a `String` parameter. – Andreas Jun 17 '16 at 01:54
@Andreas 1)No, I won't. 2)Added a string as parameter. – Eugene S Jun 17 '16 at 01:59
`import static java.lang.System.out` only means that you can reference `out` without qualification. It does *not* add `println()` to the namespace. Compile error: *The method println(String) is undefined* – Andreas Jun 17 '16 at 02:01

java difference between system.out.println() and println()

2 Answers2