HashMap add method

HashMapAdd

public class HashMap<K,V>
    extends AbstractMap<K,V>
    implements Map<K,V>, Cloneable, Serializable
{

    public V put(K key, V value) {
        if(key is already present in map) {
            return oldValue;
        }
        
        // add new entry in hashMap
        return null;
    }
    
}