What are the differences between vector, arraylist, and arraylist?

What are the differences between vector, arraylist, and arraylist?

Sort list class

The listlist interface allows null Element. In addition, the values list provides additional get, remove, and insert methods at the beginning or end of the values list. The consumer list is not synchronized (not thread-safe ). Implement thread security: List list = Collections.synchronizedList( new  LinkedList(...)); Fast addition, deletion, and slow query. ArrayList class ArrayList implements an array of variable sizes. It allows null 。 ArrayList is not synchronized. Slow addition, deletion, and fast query. Vector Vector thread security. Low Efficiency  The differences between ArrayList and Vector are as follows:
1. When the memory of ArrayList is insufficient, the default number is 50% + 1, and the Vector is doubled by default.
2. Vector provides the indexOf (obj, start) interface, which is not available in ArrayList.
3. Vector is thread-safe, but Vector is not used in most cases, because thread security requires greater system overhead.