Exercise 12 ✔

Author: viktorvoltz

Containers/com/viktorvoltz/Exercise12.java

@@ -0,0 +1,96 @@
+package com.viktorvoltz;
+
+import java.util.*;
+
+public class Exercise12<K,V> {
+	private Object[][] pairs;
+	private int index;	
+	public Exercise12(int length) {
+		pairs = new Object[length][2];
+	}
+	public void put(K key, V value) {
+		if(index >= pairs.length)
+			throw new ArrayIndexOutOfBoundsException();
+		pairs[index++] = new Object[] { key, value };
+	}
+	@SuppressWarnings("unchecked")
+	public V get(K key) {
+		for(int i = 0; i < index; i++)
+			if(key.equals(pairs[i][0]))
+				return (V)pairs[i][1];
+		return null; // Did not find key
+	}
+	public String toString() {
+		StringBuilder result = new StringBuilder();
+		for(int i = 0; i < index; i++) {
+			result.append(pairs[i][0].toString());
+			result.append(" : ");
+			result.append(pairs[i][1].toString());
+			if(i < index - 1)
+				result.append("\n");
+		}		
+		return result.toString();
+	}
+	public static void main(String[] args) {
+		Exercise12<String,String> map = 
+			new Exercise12<String,String>(6);
+		map.put("sky", "blue");
+		map.put("grass", "green");
+		map.put("ocean", "dancing");
+		map.put("tree", "tall");
+		map.put("earth", "brown");
+		map.put("sun", "warm");
+		try {
+			map.put("extra", "object"); // Past the end
+		} catch(ArrayIndexOutOfBoundsException e) {
+			System.out.println("Too many objects");
+		}
+		System.out.println(map);
+		System.out.println(map.get("ocean"));
+		HashMap<String,String> hashMap = 
+			new HashMap<String,String>(6);
+		hashMap.put("sky", "blue");
+		hashMap.put("grass", "green");
+		hashMap.put("ocean", "dancing");
+		hashMap.put("tree", "tall");
+		hashMap.put("earth", "brown");
+		hashMap.put("sun", "warm");
+		try {
+			hashMap.put("extra", "object"); // Past the end
+		} catch(ArrayIndexOutOfBoundsException e) {
+			System.out.println("Too many objects");
+		}
+		System.out.println(hashMap);
+		System.out.println(hashMap.get("ocean"));
+		TreeMap<String,String> treeMap = 
+			new TreeMap<String,String>();
+		treeMap.put("sky", "blue");
+		treeMap.put("grass", "green");
+		treeMap.put("ocean", "dancing");
+		treeMap.put("tree", "tall");
+		treeMap.put("earth", "brown");
+		treeMap.put("sun", "warm");
+		try {
+			treeMap.put("extra", "object"); // Past the end
+		} catch(ArrayIndexOutOfBoundsException e) {
+			System.out.println("Too many objects");
+		}
+		System.out.println(treeMap);
+		System.out.println(treeMap.get("ocean"));
+		LinkedHashMap<String,String> linkedHashMap = 
+			new LinkedHashMap<String,String>(6);
+		linkedHashMap.put("sky", "blue");
+		linkedHashMap.put("grass", "green");
+		linkedHashMap.put("ocean", "dancing");
+		linkedHashMap.put("tree", "tall");
+		linkedHashMap.put("earth", "brown");
+		linkedHashMap.put("sun", "warm");
+		try {
+			linkedHashMap.put("extra", "object"); // Too far
+		} catch(ArrayIndexOutOfBoundsException e) {
+			System.out.println("Too many objects");
+		}
+		System.out.println(linkedHashMap);
+		System.out.println(linkedHashMap.get("ocean"));
+	}
+}