Correct syntax for main method

Question

This is a total beginners question. I am new to java and have been browsing StackOverflow and CodeReview. I am finding these two different formats being used:

example 1:

public static void main(String args[])

or
example 2:

public static void main(String[] args)

This is what I have in my course notes:

These words are called modifiers. The main() method is also preceded by the word void to indicate that it does not return any value. Also the main() method always has a list of command line arguments that can be passed to the program

main(String[] args)

which we are going to ignore for now.

So, as you can see, we have been told to ignore this for now, but I'd like to know:

Is there an actual difference between these, if so, what?

score 8 · Accepted Answer · edited Jun 20 '20 at 09:12

8

From the Java Language Specification:

The [] may appear as part of the type at the beginning of the declaration, or as part of the declarator for a particular variable, or both.

For example:
byte[] rowvector, colvector, matrix[];
This declaration is equivalent to:
byte rowvector[], colvector[], matrix[][];

edited Jun 20 '20 at 09:12

Community

1
1

answered Sep 18 '13 at 07:20

Adam Siemion

15,569
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@ThinksALot Yes, `matrix` (and `rowvector` and `colvector`) are arrays. – Adam Siemion Sep 18 '13 at 07:29

score 4 · Answer 2 · answered Sep 20 '13 at 04:51

4

Actaully there are no difference between two main-method defination and both are correct.

But by convention java prefers array declaration as String[] args rather than String args[].

So it is more conventional -

public static void main(String[] args){...}

answered Sep 20 '13 at 04:51

Subhrajyoti Majumder

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score 4 · Answer 3 · answered Sep 20 '13 at 04:55

4

main method accepts arguement in String array following ways are accepted

public static void main(String args[])
public static void main(String []args)
public static void main(String... args)

answered Sep 20 '13 at 04:55

SpringLearner

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score 1 · Answer 4 · answered Jun 03 '15 at 19:07

All these are valid declarations of the main function in Java.

public static void main(String[] args) {
    // code
}

static public void main(String[] args) {
    // code
}

static public void main(String args[]) {
    // code
}

public static void main(String[] MarkElliotZuckerberg) {
    // code
}

public static void main(String... NewYork) {
    // code
}

The keywords public and static are interchangeable but mandatory.
The parameter of the main method can take the var-args syntax.
The name can be anything..!

These are examples of invalid main method declarations -

static void main(String[] args) {
    // public is missing
}

public void main(String args[]) {
    // static is missing
}

public static int main(String... Java) {
    // return type not void

    return 0;
}

public void Main(String args[]) {
    // "main" not "Main"
}

public void main(string args[]) {
    // "String" not "string"
}

public void main(String.. SayHi) {
    // Ellipses is 3 dots !
}

I'm sorry if the source code is not soo readable... I always had trouble posting source code... :P ... Hope this helps...! If it did, let me know by commenting..!

Source - Java Tutorials on Theory of Programming

Correct syntax for main method

4 Answers4