CODEWITHSUNDEEP
javaarraysstringprogram-entry-point
Ruchira Gayan Ranaweera
Ruchira Gayan Ranaweera

Reputation: 35547

Define a String array in Java

In java we can define main() method as both these ways.

public static void main(String[] args) {          
    System.out.println("Hello World");
}

.

public static void main(String... args) {          
    System.out.println("Hello World");
}

Both method takes array of String arguments. Now consider following scenario.

    String[] arr=new String[10]; // valid
    String... arr=new String[10];// invalid

Java never allows to create an array like this wayString... arr=new String[10];. But in above method implementation java allows to do so. My question is how java achieve this two different behavior for two scenarios?

Upvotes: 0

Views: 35154

Answers (4)

Juned Ahsan
Juned Ahsan

Reputation: 68715

...

is a syntax for method arguments and not for variable definitions. The name of this notation is varargs, which is self explanatory i.e variable number of arguments.

Upvotes: 4

sanbhat
sanbhat

Reputation: 17622

... refers to varargs and its main intention to make method more readable. 

void method(String... args) {

}

can be called as

method("a"); OR method("a", "b"); OR method("a", "b", "c");

I see no point in using it in variable declaration, we can't do much with

String... a = {"a", "b"}

An array can anyways be declared with dynamic size

String[] arr = {"a"};

OR

String[] arr = {"a", "b"};

Upvotes: 1

fortran
fortran

Reputation: 76057

You can use varargs in main because a method declared with varargs (...) is bytecode compatible with a declaration of a method with an array argument (for backwards compatibility). That does not mean that the same syntax is allowed for type declarations.

Upvotes: 0

Ankur Lathi
Ankur Lathi

Reputation: 7836

Variable argument or varargs(...) in Java used to write more flexible methods which can accept as many argument as you need not for initialization.

Upvotes: 1

Related Questions