Variable Arguments in Java 5

[Rohit Bhagwat]

Hello friends

I am unable to run the following program. I dont see any compile time errors but I get runtime error. The error which I get at runtime is

java.lang.VerifyError: (class: test/Enums, method: main signature: ([Ljava/lang/String V) Unable to pop operand off an empty stack
Exception in thread "main"

I am unable to debug the problem. Can anyone please help me, as to where I am going wrong ? I am using Eclipse 3.2 IDE, so dont know if I am missing out some settings. The only settings I checked for in eclipse is ensured that Installed JRE is Java 5 and compiler is refering to Java 5.

Waiting for your replies.

Thanks
Rohit.
***************************************************************************
package test;

enum Season
{
SUMMER(40),
WINTER(15),
RAINY(28)
{
int getHumidity()
{
return 90;
}
};

Season(int temperature)
{
mTemp = temperature;
}

int getHumidity()
{
return 50;
}

private int mTemp;
}
public class Enums
{
static Season s;

public static void main(String[] args)
{
System.out.println(Season.RAINY.getHumidity());
Enums e = new Enums();
System.out.println(e.varArgs1(1));
}

public void varArgs1(int... a)
{
for (int a1 : a)
{
System.out.println(a1);
}
}
}
***************************************************************************

[megha joshi]

Hi,

The code gives compiler error at the following line...

System.out.println(e.varArgs1(1));

varAgrs() returns nothing...its return type is void...so it can't be used
in a print statement..

Changing the method varArgs1() as follows:

  
public int varArgs1(int... a)
{
for (int a1 : a)
{
System.out.println(a1);
}
return 0;
}
  

Gives the output

90
1
0

as I would expect...

What output were you looking for?
Thanks,
Megha
[ April 30, 2007: Message edited by: megha joshi ]

[Matt Russell]

Originally posted by Rohit Bhagwat:

    
...
System.out.println(e.varArgs1(1));
...    
public void varArgs1(int... a)
...

I don't know why Eclipse isn't picking it up (it does for me on v3.2.1), but the varArgs1() method doesn't return any value, so you should be getting a compile error on the System.out.println() line.

[Barry Gaunt]

On this line:

 System.out.println(e.varArgs1(1));   

I get the compiler error "'void' type not allowed here" as expected. That's using Java jdk 1.6 compiler. And if you fix that by specifying a String to be returned by the method, then you had better return a String.

Eclipse 3.2.2 finds the same error.
[ May 01, 2007: Message edited by: Barry Gaunt ]

[Burkhard Hassel]

Eclipse 3.1 with Java5 (eclipse's own compiler) also finds the problem with printing out a void.

Bu.

[Rohit Bhagwat]

Friends, I am very sorry. Indeed I am wondering how eclipse didnt gave me compile time error !! Because had eclipse given me compile time error, I wouldnt have been into so much of trouble of getting the answer as to why I am getting the following error.

java.lang.VerifyError: (class: test/Enums, method: main signature: ([Ljava/lang/String V) Unable to pop operand off an empty stack
Exception in thread "main"

This error has totally misguided me.. Indeed the following statement
System.out.println(e.varArgs1(1));
must give error, if the method returns void. Sorry for overlooking this statement.

Thanks all, for your replies, now I am able to see the output as expected...

Thanks
Rohit.
[ May 01, 2007: Message edited by: Rohit Bhagwat ]

[Marcus Green]

Although Eclipse (and NetBeans) are very good for production coding, for the purpose of studying for the exam you should probably use the basic JDK. I have had a steady trickle of questions from people who find the results when using Eclipse differ from using a basic editor and the JDK.
[ May 01, 2007: Message edited by: Marcus Green ]