10. HashTable

HashTable

• put (k,v) : 放入 (k,v)

• get (k) : return v

HashSet and HashMap

若要改寫hash function計算對象，必須在class改寫equals() and hashCode()

@Override
public boolean equals (Object obj){
    if (obj == null || !(obj instanceof ContactList)){
        return false;
    }
    return new HashSet(names).equals(new HashSet(((ContactList)obj).names));
}

@Override
public int hashCode(){
    return new HashSet(names).hashCode();
}