Added Associative Collection practice programmes

Author: jimmy17x

bin/associativeCollection/Exercise.class

@@ -0,0 +1,68 @@
+package associativeCollection;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.TreeMap;
+
+public class Exercise {
+
+	public static void main(String[] args) {
+
+		String text = "Either the well was very deep or she fell very slowly "
+				+ "for she had plenty of time as she went down to look about "
+				+ "her and to what was going to happen next First "
+				+ "she tried to look down and make out what she was coming to "
+				+ "but it was too dark to see anything then she looked at the "
+				+ "sides of the well and noticed that they were filled with "
+				+ "cupboards and book-shelves here and there she saw maps and "
+				+ "pictures hung upon pegs She took down a jar from one of the  "
+				+ "shelves as she passed it was labeled orange marmalade but "
+				+ "to her great disappointment it was empty she did not like to "
+				+ "drop the jar for fear of killing somebody underneath so "
+				+ "managed to put it into one of the cupboards as she fell past";
+
+		String words[] = text.split(" ");
+		Arrays.sort(words);
+
+		int count = 0;
+		for (String s : words)
+			System.out.println(s);
+
+		// keep record of how many times a word came in text
+		TreeMap<String, Integer> wordList = new TreeMap<String, Integer>();
+		String thisWord = "";
+		String nextWord = "";
+
+		for (int i = 0; i < words.length - 1; ++i) {
+			thisWord = words[i];
+			++count;
+			nextWord = words[i + 1];
+
+			if (!thisWord.equals(nextWord)) {
+				wordList.put(thisWord, count);
+				count = 0;
+			}
+		}
+
+		// handle odd number of words
+		if (((words.length) & 1) != 0) {
+			nextWord = words[words.length - 1];
+			if (thisWord.equals(nextWord))
+				++count;
+			else
+				count = 1;
+
+			wordList.put(nextWord, count);
+		}
+
+		Set set = wordList.entrySet();
+		Iterator i = set.iterator();
+		while (i.hasNext()) {
+			Entry entry = (Entry) i.next();
+			System.out.println(entry.getKey() + " : " + entry.getValue());
+		}
+
+	}
+}

bin/associativeCollection/NumbersHashMap.class

@@ -0,0 +1,35 @@
+package associativeCollection;
+
+import java.util.HashMap;
+import java.util.Map.Entry;
+
+//order of elements is unpredictable in HashMaps
+public class NumbersHashMap {
+
+	public static void main(String[] args) {
+		HashMap<String, String> map = new HashMap();
+		map.put("marshal", "7876");
+		map.put("Jimmy", "7876");
+		map.put("jolly", "7876");
+
+		map.put("ozzy", "7876");
+		map.put("scarfield", "7876");
+
+		System.out.println("Jimmy's number is " + map.get("Jimmy"));
+		System.out.println("Size is " + map.size());
+
+		if (map.containsKey("Jimmy")) {
+			map.remove("Jimmy");
+			System.out.println("Do map contains number for jimmy ? " + "yes");
+			System.out.println("Successfully removed");
+
+		}
+		for (Entry<String, String> entry : map.entrySet()) {
+			System.out.println(entry.getKey() + " : " + entry.getValue());
+		}
+
+		System.out.println("Size is " + map.size());
+
+	}
+
+}

bin/associativeCollection/NumbersTreeMap.class

@@ -0,0 +1,33 @@
+package associativeCollection;
+
+
+//treemap will keep items in order
+import java.util.Map.Entry;
+import java.util.TreeMap;
+
+public class NumbersTreeMap {
+
+	public static void main(String[] args) {
+		TreeMap <String , String> map = new TreeMap();
+		map.put("marshal", "7876");
+		map.put("Jimmy", "7876");
+		map.put("jolly", "7876");
+		
+		map.put("ozzy", "7876");
+		map.put("scarfield", "7876");
+		
+		System.out.println("Jimmy's number is " + map.get("Jimmy"));
+		System.out.println("Size is " + map.size());
+		for(Entry<String, String> entry : map.entrySet())
+		{
+			System.out.println(entry.getKey() + " : " +entry.getValue());
+		}
+		map.remove("Jimmy");
+		
+		
+		System.out.println("Size is " + map.size());
+
+		
+	}
+
+}