Deque Examples

Deque Examples

Deque 1 - Construction, enumeration, access, pushing, popping.

Deque 2 - Counting, finding, erasing, replacing, removing.

Deque 3 - Insertion.

Deque 4 - Exceptions. 

Deque1 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import java.util.Enumeration;
import jgl.*;

/**
 * Construction, enumeration, access, pushing, popping. 
 * 

 * @see jgl.Deque
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Deque1
  {
  public static void main( String[] args )
    {
    Deque deque = new Deque();
    deque.pushBack( "bat" );
    deque.add( "cat" );
    deque.pushFront( "ape" );
    System.out.println( deque );
    System.out.println();

    System.out.println( "Enumerate the Deque" );    
    Enumeration e = deque.elements();
    while( e.hasMoreElements() )
      System.out.println( e.nextElement() );
    System.out.println();

    System.out.println( "Iterate through the Deque" );
    for( DequeIterator i = deque.begin(); !i.equals( deque.end() ); i.advance() )
      System.out.println( i.get() );
    System.out.println();

    System.out.println( "Demonstrate access" );
    System.out.println( "deque.at( 0 ) = " + deque.at( 0 ) );
    System.out.println( "deque.front() = " + deque.front() );
    System.out.println( "deque.at( 2 ) = " + deque.at( 2 ) );
    System.out.println( "deque.back() = " + deque.back() );
    System.out.println();

    System.out.println( "Demonstrate modification" );
    deque.put( 1, "fox" );
    System.out.println( deque );

    deque.popFront();
    System.out.println( "After popFront() = " + deque );

    deque.popBack();
    System.out.println( "After popBack() = " + deque );
    }
  }

Deque1 Example Output
Deque( ape, bat, cat )

Enumerate the Deque
ape
bat
cat

Iterate through the Deque
ape
bat
cat

Demonstrate access
deque.at( 0 ) = ape
deque.front() = ape
deque.at( 2 ) = cat
deque.back() = cat

Demonstrate modification
Deque( ape, fox, cat )
After popFront() = Deque( fox, cat )
After popBack() = Deque( fox )


Deque2 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import jgl.*;

/**
 * Counting, finding, erasing, replacing, removing.
 * 

 * @see jgl.Deque
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Deque2
  {
  public static void main( String[] args )
    {
    Deque deque = new Deque();
    deque.add( "ape" );
    deque.add( "bat" );
    deque.add( "cat" );
    deque.add( "bat" );
    deque.add( "bat" );
    deque.add( "cat" );
    System.out.println( deque );
    System.out.println();

    System.out.println( "deque.count( bat ) = " + deque.count( "bat" ) );
    int index = deque.indexOf( "bat" );
    System.out.println( "deque.indexOf( bat ) = " + index );
    deque.remove( index );
    System.out.println( "After deque.remove( " + index + " ) = " + deque );
    deque.replace( 0, 2, "bat", "BAT" );
    System.out.println( "After deque.replace( 0, 2, bat, BAT ) = " + deque );
    System.out.println( "deque.remove( cat ) = " + deque.remove( "cat" ) );
    System.out.println( "After deque.remove( cat ) = " + deque );
    deque.remove( deque.begin() );
    System.out.println( "After deque.remove( begin() ) = " + deque );
    }
  }


Deque2 Example Output
Deque( ape, bat, cat, bat, bat, cat )

deque.count( bat ) = 3
deque.indexOf( bat ) = 1
After deque.remove( 1 ) = Deque( ape, cat, bat, bat, cat )
After deque.replace( 0, 2, bat, BAT ) = Deque( ape, cat, BAT, bat, cat )
deque.remove( cat ) = 2
After deque.remove( cat ) = Deque( ape, BAT, bat )
After deque.remove( begin() ) = Deque( BAT, bat )


Deque3 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import jgl.*;

/**
 * Insertion.
 * 

 * @see jgl.Deque
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Deque3
  {
  public static void main( String[] args )
    {
    Deque deque = new Deque();
    deque.add( "bat" );
    deque.add( "cat" );
    deque.add( "dog" );
    System.out.println( "deque = " + deque );
    System.out.println();

    deque.insert( deque.begin(), "ape" );
    System.out.println( "After insert at begin = " + deque );

    deque.insert( deque.end(), "emu" );
    System.out.println( "After insert at end = " + deque );

    deque.insert( 3, 2, "fox" );
    System.out.println( "After deque.insert( 3, 2, fox ) = " + deque );
    }
  }

Deque3 Example Output
deque = Deque( bat, cat, dog )

After insert at begin = Deque( ape, bat, cat, dog )
After insert at end = Deque( ape, bat, cat, dog, emu )
After deque.insert( 3, 2, fox ) = Deque( ape, bat, cat, fox, fox, dog, emu )


Deque4 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import jgl.*;

/**
 * Exceptions.
 * 

 * @see jgl.Deque
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Deque4
  {
  public static void main( String[] args )
    {
    Deque deque = new Deque();
    try
      {
      deque.popBack();
      }
    catch( InvalidOperationException exception )
      {
      System.out.println( "Caught " + exception );
      }
    deque.add( "ape" );
    deque.add( "bat" );
    deque.add( "cat" );
    try
      {
      deque.at( 5 );
      }
    catch( IndexOutOfBoundsException exception )
      {
      System.out.println( "Caught " + exception );
      }
    
    }
  }

Deque4 Example Output
Caught jgl.InvalidOperationException: Deque is empty
Caught java.lang.IndexOutOfBoundsException: Attempt to access index 5 when valid range is 0..2