associativearray.java

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package the10;

//: 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.
 
//import com.bruceeckel.simpletest.*;

public class AssociativeArray {
// private static Test monitor = new Test();
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"));
/**  monitor.expect(new String[] {
   "Too many objects!",
   "sky : blue",
   "grass : green",
   "ocean : dancing",
   "tree : tall",
   "earth : brown",
   "sun : warm",
   "dancing"
 });*/
}
} ///:~