What is the correct Java main() method parameters syntax?

Question

Is there a functional difference between these methods?

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

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

Answer 1

There is no difference, but the first one is according to standard.

Answer 2

There is not a difference between the 2 choices you can do either one of them.

You could also put this:

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

Answer 3

Different Array notations

The notation

String args[]

is just a convenience for C programmers, but it's identical to this notation:

String[] args

Here's what the Sun Java Tutorial says:

You can also place the square brackets after the array's name:

float anArrayOfFloats[]; // this form is discouraged

However, convention discourages this form; the brackets identify the array type and should appear with the type designation.

Reference: Java Tutorial > Arrays

VarArgs

BTW, a lesser known fact is that main methods also support varargs, so this is also okay:

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

The reason is that a varargs method is internally identical to a method that supports a single array parameter of the specified type.E.g. this won't compile:

public static void main(final String... parameters){}
public static void main(final String[] parameters){}
// compiler error: Duplicate method main(String[])

Reference: Java Tutorial > Arbitrary Number of Arguments

Answer 4

I also prefer to mark the args as final.

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

Answer 5

No, but the first is the prefered style.

Edit: Another option is

public static void main(String... args)

which additionally allows callers to use varargs syntax.

Answer 6

Use String[] instead of use [] postfix to reference. Infact String[] obj; hilights the fact that obj is a reference of type String[] (array of String).