Main Method

[jaspreet manchinda]

Hello Everyone,
can anyone please tell me what is difference between
1.public static void main ();
2.public static void main(String args []);
3.public static void main (String... args);
i know its kind of noob question but i am little confused with it

[Anayonkar Shivalkar]

jaspreet manchinda wrote:Hello Everyone,
can anyone please tell me what is difference between
1.public static void main ();
2.public static void main(String args []);
3.public static void main (String... args);
i know its kind of noob question but i am little confused with it

1. A public, static and void method named main which takes no arguments.
2. A public, static and void method named main which takes argument as array of String. This method also acts as entry point of program (if main class is proper et-cetera)
3. Same as 2. Only syntax is different. Instead of String array, here there's usage of var-args.

I hope this helps.

[jaspreet manchinda]

Quote:

Same as 2. Only syntax is different. Instead of String array, here there's usage of var-args.

thank you for your reply but when to use main without argument and when to use wit var-args

[Vinod Vijay]

jaspreet manchinda wrote:Quote:

Same as 2. Only syntax is different. Instead of String array, here there's usage of var-args.

thank you for your reply but when to use main without argument and when to use wit var-args

Your java program execution always begin with standard main method with standard arguments i.e. public static void main(String[] args){}.
But you can at any no. of times overload main method in your same program as per your requirements.

I hope it is clear to you now.

[jaspreet manchinda]

yeah!! its much more clear now thanks for your replies guys

[Aj Maven]

jaspreet manchinda wrote:Hello Everyone,
can anyone please tell me what is difference between
1.public static void main ();
2.public static void main(String args []);
3.public static void main (String... args);
i know its kind of noob question but i am little confused with it

1. Is a normal method which is being used in the program and is not the point of entry of execution of the program, having this method. Its just a static method.
2. This is the method which is the point of entry for execution of a program. Execution will start from here.
3. String args[] holds the same meaning as String ... args, where the later is called var-ags which takes or holds multiple values of type String. All that is said in '2', applies here too.

[Vishal Hegde]

class t1
{
  public static void main()
  {
  }

}

At compile time this code will work fine

But at run time you will get an Exception.

Remember Exceptions come during Runtime

[Vinod Vijay]

Vishal Hegde wrote:

class t1
{
  public static void main()
  {
  }

}

At compile time this code will work fine

But at run time you will get an Exception.

Remember Exceptions come during Runtime

Ofcourse, it will compile because no syntax or Java rule violations. But will not run because the interpretor could not locate standard main().

[Vishal Hegde]

Vinod Vijay wrote:

Vishal Hegde wrote:

class t1
{
  public static void main()
  {
  }

}

At compile time this code will work fine

But at run time you will get an Exception.

Remember Exceptions come during Runtime

Ofcourse, it will compile because no syntax or Java rule violations. But will not run because the interpretor could not locate standard main().

Thats what I was conveying

[fred rosenberger]

Vishal Hegde wrote:

class t1
{
  public static void main()
  {
  }

}

Note that the above is no different than

class t1
{
  public static void fred()
  {
  }

}

The larger point here is that main() is no different from any other method. You can overload it, you have have it or even not have it. It is all valid java. The only time it matters is when you want to START your program. The JVM looks for the main method with the signature of "public static void main(String [] args)"

[Vinod Vijay]

Vishal Hegde wrote:

Vinod Vijay wrote:

Vishal Hegde wrote:

class t1
{
  public static void main()
  {
  }

}

At compile time this code will work fine

But at run time you will get an Exception.

Remember Exceptions come during Runtime

Ofcourse, it will compile because no syntax or Java rule violations. But will not run because the interpretor could not locate standard main().

Thats what I was conveying

I know, just added my words to that