Passing arrays and individual array elements to methods

import java.awt.Container;
import javax.swing.*;

public class PassArray extends JApplet 
     {
     JTextArea outputArea;
     String output;
    
     public void init()
         {
         outputArea = new JTextArea();
         Container c = getContentPane();
         c.add( outputArea );
        
         int a[] = { 1, 2, 3, 4, 5 };
        
         output = "Effects of passing entire " + "array call-by-reference:\n" +
         "The values of the original array are:\n";
        
         for ( int i = 0; i < a.length; i++ )
         output += " " + a[ i ];
        
         modifyArray( a ); // array a passed call-by-reference
        
         output += "\n\nThe values of the modified array are:\n";
        
         for ( int i = 0; i < a.length; i++ )
         output += " " + a[ i ];
        
         output += "\n\nEffects of passing array " + "element call-by-value:\n" +
         "a[3] before modifyElement: " + a[ 3 ];
        
         modifyElement( a[ 3 ] );
        
         output += "\na[3] after modifyElement: " + a[ 3 ];
         outputArea.setText( output );
     }
    
     public void modifyArray( int b[] )
         {
         for ( int j = 0; j < b.length; j++ )
         b[ j ] *= 2;
     }
    
     public void modifyElement( int e )
         {
         e *= 2;
     }
}