Larry Larry - 3 months ago 18
Java Question

HashMap to return default value for non-found keys?

Is it possible to have a

HashMap
return a default value for all keys that are not found in the set?

Answer

There's no Map implementation that does this exactly but it would be trivial to implement your own by extending HashMap:

public class DefaultHashMap<K,V> extends HashMap<K,V> {
  protected V defaultValue;
  public DefaultHashMap(V defaultValue) {
    this.defaultValue = defaultValue;
  }
  @Override
  public V get(Object k) {
    return containsKey(k) ? super.get(k) : defaultValue;
  }
}