Java中HashMap里面key为null存放到哪

// HashMap的put方法

  public V put(K key, V value) {

     if (table == EMPTY_TABLE) {

       inflateTable(threshold);

     }

     if (key == null )

        // key为null调用putForNullKey(value)

        return putForNullKey(value);

     int hash = hash(key);

     int i = indexFor(hash, table.length);

     for (Entry<K,V> e = table[i]; e != null ; e = e.next) {

       Object k;

       if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {

         V oldValue = e.value;

         e.value = value;

         e.recordAccess( this );

         return oldValue;

       }

     }

     modCount++;

     addEntry(hash, key, value, i);

     return null ;

   }

/**

   * Offloaded version of put for null keys

   */

  private V putForNullKey(V value) {

    for (Entry<K,V> e = table[ 0 ]; e != null ; e = e.next) {

      if (e.key == null ) {

        V oldValue = e.value;

        e.value = value;

        e.recordAccess( this );

        return oldValue;

      }

    }

    modCount++;

    addEntry( 0 , null , value, 0 );

    return null ;

  }