Maps/UnsortedArrayMap - Revision history

Admin: Replacing charlesreid1.com:3000 with git.charlesreid1.com

2019-10-09T03:39:30Z

Replacing charlesreid1.com:3000 with git.charlesreid1.com

← Older revision		Revision as of 03:39, 9 October 2019
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	==Git link==		==Git link==

	The unsorted array implementation of a map is at git.charlesreid1.com: https://charlesreid1.com~~:3000~~/cs/java/src/master/hash/UnsortedArrayMap.java		The unsorted array implementation of a map is at git.charlesreid1.com: https://git.charlesreid1.com/cs/java/src/master/hash/UnsortedArrayMap.java

	This implements the Map ADT - see [[Maps/ADT]].		This implements the Map ADT - see [[Maps/ADT]].

Admin at 03:37, 26 June 2017

2017-06-26T03:37:57Z

← Older revision		Revision as of 03:37, 26 June 2017
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	</pre>		</pre>

			=Flags=






	{{MapsFlag}}		{{MapsFlag}}

Admin: /* Code */

2017-06-26T03:36:41Z

Code

← Older revision		Revision as of 03:36, 26 June 2017
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	This implements the Map ADT - see [[Maps/ADT]].		This implements the Map ADT - see [[Maps/ADT]].

	==~~Code~~==		==Java implementation==

	The class below, as with most classes, is organized as follows:		The class below, as with most classes, is organized as follows:

Admin: /* Code */

2017-06-26T03:33:18Z

Code

← Older revision		Revision as of 03:33, 26 June 2017
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	This implements the Map ADT - see [[Maps/ADT]].		This implements the Map ADT - see [[Maps/ADT]].

			==Code==

			The class below, as with most classes, is organized as follows:
			* Start with main method to illustrate the usage of the class, and test its functionality
			* Include any utility classes that this concrete class will use (in particular, a way to iterate over key-value pairs)
			* The class implementation (the array list)

			The code for this concrete implementation starts with a main method that briefly shows how to use this:

			<pre>
			import java.util.ArrayList;
			import java.util.Iterator;
			import java.util.NoSuchElementException;


			/**
			* Unsorted Array Map.
			*
			* A concrete implementation of the map type that stores
			* key-value items in an arraylist.
			*
			* This class is terribly inefficient, requiring O(N) lookups each time.
			*/
			public class UnsortedArrayMap<K,V> extends AbstractMap<K,V> {

			public static void main(String[] args) {
			UnsortedArrayMap<String,String> m = new UnsortedArrayMap<>();
			m.put("WAT","monkey");
			m.put("WHO","tree");
			m.put("WHY","sticks");
			System.out.println(m.size());
			System.out.println(m.get("WHO"));
			}

			</pre>

Admin at 03:29, 26 June 2017

2017-06-26T03:29:32Z

← Older revision		Revision as of 03:29, 26 June 2017
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	* MapItem class was actually protected and lived in AbstractMap class		* MapItem class was actually protected and lived in AbstractMap class
	* Therefore, we had to hold off declaring an abstract MapItem iterator until the AbstractMap class, not the Map interface		* Therefore, we had to hold off declaring an abstract MapItem iterator until the AbstractMap class, not the Map interface

			=Code=

			==Git link==

			The unsorted array implementation of a map is at git.charlesreid1.com: https://charlesreid1.com:3000/cs/java/src/master/hash/UnsortedArrayMap.java

			This implements the Map ADT - see [[Maps/ADT]].

Admin at 01:17, 26 June 2017

2017-06-26T01:17:41Z

← Older revision		Revision as of 01:17, 26 June 2017
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	Define the UnsortedArrayMap class, the concrete implementation of the abstract map that utilizes an array list to store items in the map.		Define the UnsortedArrayMap class, the concrete implementation of the abstract map that utilizes an array list to store items in the map.

			==Abstract map implementation notes==

			The process of defining the abstract map:
			* Needed to define a map item wrapper class, of course
			* This is designed to take a K,V key value pair
			* Also need to define four more classes:
			* Two Iterators and two Iterables

			Iterators vs Iterables - ?
			* Map key Iterator object
			* Map value Iterator object
			* Map key Iterable object (?) - thought I understood this, but maybe not?
			* Map value Iterable object (?)
			* The Iterator objects are like mini-scanners.
			* The Iterable objects just have an iterator() method and are what are actually returned.

			entrySet:
			* Note that the key and value sets use the entrySet method
			* We aren't defining entrySet, just using it
			* entrySet must be defined in our concrete class
			* This means we have three total Iterators and three total Iterables

			More iterators vs iterables:
			* Iterable just says, I return an Iterator. it is part of the core language.
			* Iterator has to be defined for each container.

			Exceptions:
			* NoSuchElementException
			* UnsupportedOperationException
			* Don't forget to check for size!
			* Especially if you are not wraapping someone else's iterator

			Ordering of class declaration and undeclared class declarations
			* I could not use MapItem class undefined in the Map interface (most generic of all)
			* MapItem class was actually protected and lived in AbstractMap class
			* Therefore, we had to hold off declaring an abstract MapItem iterator until the AbstractMap class, not the Map interface

Admin: /* Notes */

2017-06-25T23:20:13Z

Notes

← Older revision		Revision as of 23:20, 25 June 2017
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	This map has terrible performance, and is purely implemented for illustrative reasons.		This map has terrible performance, and is purely implemented for illustrative reasons.

			==Procedure==

			Notes for implementation procedure in Java.

			Start by defining, on paper, what the map ADT is going to look like. See [[Maps/ADT]].

			Define the Map interface class that establishes the basic PUBLIC functionality all Map objects must provide.

			Define an AbstractMap abstract class that creates any utility classes (item or position classes, iterators, iterables) and any additional fields or methods (particularly PROTECTED) that should be implemented.

			Define the UnsortedArrayMap class, the concrete implementation of the abstract map that utilizes an array list to store items in the map.

Admin at 23:07, 25 June 2017

2017-06-25T23:07:00Z

← Older revision		Revision as of 23:07, 25 June 2017
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	This map has terrible performance, and is purely implemented for illustrative reasons.		This map has terrible performance, and is purely implemented for illustrative reasons.




			{{MapsFlag}}
			[[Category:Maps]]
			[[Category:Arrays]]
			[[Category:Java]]

Admin: Created page with "=Notes= The unsorted array map is an implementation of a map that uses an unsorted array list to store the map items. This map has terrible performance, and is purely implem..."

2017-06-25T23:06:40Z

Created page with "=Notes= The unsorted array map is an implementation of a map that uses an unsorted array list to store the map items. This map has terrible performance, and is purely implem..."

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=Notes=

The unsorted array map is an implementation of a map that uses an unsorted array list to store the map items.

This map has terrible performance, and is purely implemented for illustrative reasons.