How String[] args different from String... args in the main method?

Question

I got confused when I saw these two techniques through which we can pass our command line argument in main method.

I have seen this link in stackoverflow but still I don't get it.

My doubt is which is efficient between these two ways.

1.In first we are calling main and assigning parameter as a string array 2.In second we are calling main with variable no of arguments.

A `String...` is syntactic sugar. It's actually wrapped in an `String[]` when it's passed into the method. — Boris the Spider, Mar 03 '14 at 00:42
http://docs.oracle.com/javase/1.5.0/docs/guide/language/varargs.html — Sinkingpoint, Mar 03 '14 at 00:42

score 4 · Accepted Answer · answered Mar 03 '14 at 00:43

4

It means that if you want to invoke the main method of a class that isn't the entry point, it's easier:

class MyProgram1 {
    public static void main(String[] args) {
        MyProgram2.main(new String[] {"arg1", "arg2", "arg3"})
    }
}

vs:

class MyProgram1 {
    public static void main(String[] args) {
        MyProgram2.main("arg1", "arg2", "arg3")
    }
}

answered Mar 03 '14 at 00:43

Eric

Dear @Eric Which is efficient and when we use String... args[]?? – Satya Mar 03 '14 at 00:53
@Satya: It's your main method. It's called once. You do __not__ care about the efficiency of that invocation. You use `String... args[]` when you want the error `legacy array notation not allowed on variable-arity parameter`. You use `String[]... args` when you want to pass a variable number of string arrays. – Eric Mar 03 '14 at 01:03

1 Answers1