call by value and call by reference

//Code=java//

Here is the code of call by value and call by reference

Code java:

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class test 
{
	void meth (int a,int b)
	{
		a*=2;
		b/=2;
	}
}
class callbyvalue 
{
	public static void main(String[] args)
	{
		test ob=new test();
		int i=15,j=20;
		System.out.println("i and j before call :" +i + " " +j);
		ob.meth(i,j);
		System.out.println("i and j after call : " + i + " " +j);
	}
}
 
class test1 
{
int a,b;
test1 (int i, int j)
{
	a=i;
	b=j;
}
void meth(test1 o)
{
o.a*=2;
o.b/=2;
}
}
	class callbyref
	{
		public static void main (String args[])
		{
			test1 ob=new test1 (15,20);
			System.out.println("ob.a and ob.b before call: " +ob.a +" " + ob.b);
			ob.meth(ob);
			System.out.println("ob.a and ob.b after call : "+ob.a +" "+ob.b);
		}

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When i compile test.java file , It compiles and gives me a run time error main method not found in test ,please define the main method as public static void main(String args[])

On the other hand , when i am compiling test1.java, it is also giving the same error.My question is main method is there in both the codes . So what do we mean by this error?

Why is it so? Please help me resolve both as i have exam . Thanks :>

//Code=Java

Quote:

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when i am compiling test 1.java, it is giving a run time error of could not load main class test 1.

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Not sure your question makes sense. It is not possible to have a space in a class name: test 1

What don't you understand about the following error message:

Quote:

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main method not found in test ,please define the main method as public static void main(String args[])

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What the java program is telling you seems very clear.

Please Edit your post and wrap your code with
[code=java]
<YOUR CODE HERE>
[/code]
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