Mega Code Archive
Associates keys with values
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// : 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"));
}
} ///:~
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