Arraylist
1、
HashTable
1、如何计算索引
int hash = key.hashCode(); int index = (hash & 0x7FFFFFFF) % tab.length;
2、扩容数量
int oldCapacity = table.length; int newCapacity = (oldCapacity << 1) + 1; Entry<?,?>[] newMap = new Entry<?,?>[newCapacity];
HashSet
内部通过HashMap实现