Reputation: 59576

Is there a difference between main(String args[]) and main(String[] args)?

Is there a difference between:

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

and

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

I don't believe so, but I am wondering.

Upvotes: 60

Answers (11)

Jawed Salim

Reputation: 344

Both of them are absolutely the same. Please refer to Java Language Specification (JLS) to see the syntax used in java.

String[] args or String args[] will create an array (reserves a place in memory) with no size and name args.

Let us Consider:

String [] x;

Putting the [] after the name avoids subtle problems like this:-

String x [] , y; //x[] is an array but y is a String
String [] x y ; //two arrays x[] and y[] both

Upvotes: 8

Marcel

Reputation: 319

String args[] and String[] args are identical. In the sense that they do the same thing, Creating a string array called args.

But to avoid confusion and enforce compatibility with all other Java codes you may encounter I'd recommend using the syntax (String[] args) when declaring arrays.

One confusion you may encounter is when you try to declare multiple String array in one line, then String[] fruits, vegetables will not be the same as String fruits[], vegetables

The former creates two string arrays fruits and vegetables, while the later creates a String array of fruits and a string variable of vegetables

Upvotes: 0

Amal K

Reputation: 4874

Apart from these two styles, it is worth mentioning that the following is also a valid signature for the main() method since Java 5:

public static void main(String... args)

From the Java Language specification:

The method main must be declared public, static, and void. It must specify a formal parameter (§8.4.1) whose declared type is array of String.

The ellipsis ... is the syntax for var-args, which can be used to pass an arbitrary number of arguments to a method. More on it here.

Upvotes: 0

parul popli

Reputation: 51

Although both are used to create array of String type but second one is more popular, because with that, you can create multiple String arrays simultaneously... E.g String[] a,b; Here you have created two String Arrays a and b simultaneously.

However

String a[],b; will create String array "a" and String variable(not array) b.

Hope this clarifies.

Upvotes: 5

ankit

Reputation: 1

there is a difference: For example if you write int[] arr; - here arr is the reference to the integer array whereas in case of int arr[]; - arr is a primitive int type array

Upvotes: -3

user2133237

Reputation: 1

The difference between these is that when we try to call the main method manually from one class to another by using static syntax , we use "string[] s ". At that point we have to pass an array of string type as argument in main method. When we are using "String... s" then there is no need to pass any string array as an argument. It will run and it doesn't matter if you pass the array as an argument or not (if you don't explicitly pass it, it is passed by itself) ... hence proved/////////

Upvotes: 0

Mehrdad Afshari

Reputation: 421978

Semantically, they are identical. However, I'd recommend using the latter syntax (String[] args) when declaring arrays. The former syntax is there mainly for compatibility with C syntax.

Since String[], as a whole, is the type of the object in Java, it's more consistent and clear not to split it up.

A similar question addresses the [] after method argument list.

Upvotes: 54