Proper terminology for Object... args

Question

I'm working in Java and the typical way you specify multiple args for a method is:

public static void someMethod(String[] args)

But, I've seen another way a few times, even in the standard Java library. I don't know how to refer to this in conversation, and googling is not of much help due to the characters being used.

public static void someMethod(Object... args)

I know this allows you to string a bunch or arguments into a method without knowing ahead of time exactly how many there might be, such as:

someMethod(String arg1, String arg2, String arg3, ... etc

How do you refer to this type of method signature setup? I think it's great and convenient and want to explain it to some others, but am at a lack of how to refer to this. Thank you.

See [varargs](http://docs.oracle.com/javase/7/docs/technotes/guides/language/varargs.html) — Reimeus, May 21 '13 at 15:43

score 21 · Accepted Answer · answered May 21 '13 at 15:43

21

This way to express arguments is called varargs, and was introduced in Java 5.
You can read more about them here.

answered May 21 '13 at 15:43

Keppil

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Looks like C/C++ main functions – huseyin tugrul buyukisik May 21 '13 at 15:45
@huseyintugrulbuyukisik ? in C/C++ main function is either `main( void )` or `main( int argc, char *argv[] )` ... not quite the same... unless I'm missing something? – SnakeDoc May 21 '13 at 16:54

score 8 · Answer 2 · answered May 21 '13 at 17:24

As a Keppil and Steve Benett pointed out that this java feature is called varargs.

If I'm not mistaken, Joshua Bloch mentioned that there is a performance hit for using varargs and recommends telescoping and using the varargs method as a catch all sink.

public static void someMethod(Object arg) {
    // Do something
}

public static void someMethod(Object arg1, Object arg2) {
    // Do something
}

public static void someMethod(Object arg1, Object arg2, Object arg3) {
    // Do something
}

public static void someMethod(Object ... args) {
    // Do something
}

+1 great addition to this conversation. I think this is the link from Jashua Bloch: http://jtechies.blogspot.com/2012/07/item-42-use-varargs-judiciously.html Makes sense, and this seems to be a good way to go about the varags with performance in mind. — SnakeDoc, May 21 '13 at 17:33

score 5 · Answer 3 · answered May 21 '13 at 15:44

5

The Parameter method(Object... args) is called varargs. Try this link.

answered May 21 '13 at 15:44

Steve Benett

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Proper terminology for Object... args

3 Answers3

Linked