AssociativeArray.java Source code

Introduction

Here is the source code for AssociativeArray.java

Source

// : c10:AssociativeArray.java
// Associates keys with values.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.

public class AssociativeArray {

    private Object[][] pairs;

    private int index;

    public AssociativeArray(int length) {
        pairs = new Object[length][2];
    }

    public void put(Object key, Object value) {
        if (index >= pairs.length)
            throw new ArrayIndexOutOfBoundsException();
        pairs[index++] = new Object[] { key, value };
    }

    public Object get(Object key) {
        for (int i = 0; i < index; i++)
            if (key.equals(pairs[i][0]))
                return pairs[i][1];
        throw new RuntimeException("Failed to find key");
    }

    public String toString() {
        String result = "";
        for (int i = 0; i < index; i++) {
            result += pairs[i][0] + " : " + pairs[i][1];
            if (i < index - 1)
                result += "\n";
        }
        return result;
    }

    public static void main(String[] args) {
        AssociativeArray map = new AssociativeArray(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"));

    }
} ///:~