Exception in thread "main" Java.lang.NoSuchMethodError: main?

Question

import java.io.*;
import java.lang.Math;
class Squr
{
  public static void main ()
  { 
   int m =10,n;
   double z = 10.4,p;
   Squr square = new Squr();
   p = (double)square.mysqrt(z);
   n = (int)square.mysqrt(m);
   System.out.println ("square root of 10 : " + n );
   System.out.println ("square root of 10.4 : "+ p );  
  }
    double mysqrt (double y)
   {
     return Math.sqrt(y);
   }
   int mysqrt (int x)
   {
     return (int)Math.sqrt(x);
   }

}

This code is compiling but when we try to execute it it giving " Exception in thread "main" Java.lang.NoSuchMethodError: main "

Pay (close) attention to the error messages and full-type signatures. Happy coding. — , Jan 28 '11 at 11:45
This Community Wiki question lists the possible causes of this common problem: http://stackoverflow.com/questions/5407250/causes-of-java-lang-nosuchmethoderror-main-exception-in-thread-main — Stephen C, Jun 28 '11 at 14:39

score 7 · Accepted Answer · edited Jun 30 '12 at 04:00

7

The main() function should be declared like this

public static void main(String[] args)

edited Jun 30 '12 at 04:00

nhahtdh

55,989
15
126
162

answered Jan 28 '11 at 10:18

DoctorRuss

1,429
10
9

score 4 · Answer 2 · answered Jan 28 '11 at 10:19

4

The correct method signature for the main method in Java is:

public static void main(String args[])

Simply add the missing arguments in you method declaration and it should work.

answered Jan 28 '11 at 10:19

Andreas Dolk

113,398
19
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score 2 · Answer 3 · answered Jan 28 '11 at 10:20

2

Try that:

public static void main(String [ ] args)

answered Jan 28 '11 at 10:20

nrph

335
7
18

score 2 · Answer 4 · answered Jan 28 '11 at 10:21

2

It looks like you've not defined your main method with the correct signature. It should be:

public class Squr
{
  public static void main(String[] args)

answered Jan 28 '11 at 10:21

John Pickup

5,015
2
22
15

score 2 · Answer 5 · answered Jan 28 '11 at 10:23

2

Your main() method should be like that

public static void main(String args[])

or

public static void main(String[] args)

or

public static void main(String... args)

answered Jan 28 '11 at 10:23

Above two suggestion public static void main(String args[]) and public static void main(String[] args) is working well but not third one... – Nishant Kumar Jan 28 '11 at 10:27
It should work. It works for me. Here is demo http://ideone.com/OhZvh – Jan 28 '11 at 10:33
Note that the 3rd option will only compile when using Java 5+ as that is when the varargs (...) notation was introduced. – Michael Rutherfurd Feb 08 '11 at 23:39

score 1 · Answer 6 · edited May 04 '11 at 17:03

1

Java is a strong type language. You must declare the method in a given way. The right way to define the main() method is:

public static void main (String[] args)

edited May 04 '11 at 17:03

user unknown

35,537
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answered May 03 '11 at 19:49

Bhanu

11
2

There are already 5, nearly identical answers. Can you point out what is new in your answer? Couldn't you comment on one of the other posts? If you agree with another post, vote it up, but don't repeat it, especially not 3 months later. Thank you. – user unknown May 04 '11 at 17:07

Exception in thread "main" Java.lang.NoSuchMethodError: main?

6 Answers6

Try that:

Linked

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