Generics Hmmmmm easy yet i don't understand :)

[gautamz07]

import java.util.*;
 
public class SetDemo {
 
  public static void main(String args[]) { 
     int count[] = {34, 22,10,60,30,22};
     Set<Integer> set = new HashSet<Integer>(); // What does this line really tell the compiler 
     try{
        for(int i = 0; i<5; i++){
           set.add(count[i]);
        }
        System.out.println(set);
 
     }
     catch(Exception e){}
  }
} 
 
 

Set<Integer> set = new HashSet<Integer>();

What Does The Abouve Line really do or tell the compiler .

public class GenericMethodTest
{
 
   public static < E > void printArray( E[] inputArray )
   {
      // Display array elements              
         for ( E element : inputArray ){        
            System.out.printf( "%s ", element );
         }
         System.out.println();
    }
 
    public static void main( String args[] )
    {
        // Create arrays of Integer, Double and Character
        Integer[] intArray = { 1, 2, 3, 4, 5 };
        Double[] doubleArray = { 1.1, 2.2, 3.3, 4.4 };
        Character[] charArray = { 'H', 'E', 'L', 'L', 'O' };
 
        System.out.println( "Array integerArray contains:" );
        printArray( intArray  ); 
 
        System.out.println( "\nArray doubleArray contains:" );
        printArray( doubleArray ); 
 
        System.out.println( "\nArray characterArray contains:" );
        printArray( charArray ); 
    } 
}
 

public static < E > void printArray( E[] inputArray )

I Understand that becasue of the above generic meathod we don't have to write 3 overloaded meathods to print out an array of characters , integers and Double . But what does it really tell the compiler .

[r035198x]

It tells the compiler that the set only contains objects of type Integer so there will be compilation errors if you try to add e.g Strings to the set.