Java Coding Problems

114. Comparing two maps

Comparing two maps is straightforward as long as we rely on the Map.equals() method. When comparing two maps, this method compares the keys and values of them using the Object.equals() method.

For example, let's consider two maps of melons having the same entries (the presence of equals() and hashCode() is a must in the Melon class):

public class Melon {  private final String type;  private final int weight;  // constructor, getters, equals(), hashCode(),  // toString() omitted for brevity}Map<Integer, Melon> melons1Map = new HashMap<>();Map<Integer, Melon> melons2Map = new HashMap<>();melons1Map.put(1, new Melon("Apollo", 3000));melons1Map.put(2, new Melon("Jade Dew", 3500));melons1Map.put(3, new Melon("Cantaloupe", 1500)); ...