Unable to compile the Generics program

[Abhimanyu Jain]

import java.util.Scanner;

class GenMeth
{
	int temp;
	<T extends Number, V extends T> void arraySort(V[] y)
	{
		for(int i=0;i<y.length;i++)
		{
			for(int j=i;j<y.length;j++)
			{
				temp=y[i].intValue();
				y[i]=y[j];
				y[j]=temp;
			}
		}
	}

	<T extends Number, V extends T> void arrayDisplay(V[] y)
	{
		for(int i=0;i<y.length;i++)
		{
			System.out.print(" "+y[i]);
		}
	}
}

class GenericsMethod
{
	public static void main(String[] args)
	{
		Integer[] a=new Integer[10];
		Scanner sc=new Scanner(System.in);
		GenMeth gm=new GenMeth();
		System.out.println("Enter the values in the array ");
		for(int i=0;i<10;i++)
		{
			a[i]=sc.nextInt();
		}
		gm.arrayDisplay(a);
		gm.arraySort(a);
		gm.arrayDisplay(a);
	}
}			

Hi, I am getting the error message as follows while trying to compile the above program

"int cannot be converted to V
y[j]=temp"

Please help :-)

[Matthew Brown]

It seems a fairly clear message. On this line:

y[j]=temp

temp is of type int, and y[j] is of type V. V can be Number or any subclass of it, so the compiler can't tell that's going to work.

[Abhimanyu Jain]

Thank you!! I fixed it and it working now. Here is the corrected code

import java.util.Scanner;

class GenMeth
{
	<T extends Number, V extends T> void arraySort(V[] y)
	{
		V temp; 
		for(int i=0;i<y.length;i++)
		{
			for(int j=i+1;j<y.length;j++)
			{
				if(y[i].intValue()>y[j].intValue())
				{
					temp=y[j];
					y[j]=y[i];
					y[i]=temp;
				}
			}
		}
	}

	<T extends Number, V extends T> void arrayDisplay(V[] y)
	{
		for(int i=0;i<y.length;i++)
		{
			System.out.print(" "+y[i]);
		}
		System.out.println();
	}
}

class GenericsMethod
{
	public static void main(String[] args)
	{
		Integer[] a=new Integer[10];
		Scanner sc=new Scanner(System.in);
		GenMeth gm=new GenMeth();
		System.out.println("Enter the values in the array ");
		for(int i=0;i<10;i++)
		{
			a[i]=sc.nextInt();
		}
		gm.arrayDisplay(a);
		gm.arraySort(a);
		gm.arrayDisplay(a);
	}
}			

[Matthew Brown]

Well done. I was wondering about your arraySort method, where you seemed to be swapping every pair regardless of what order they were in! But you've fixed that now.

[Abhimanyu Jain]

Thank you sir