What does it mean when we say Hashtable or Vector is synchronized?

Question

The questions says it all, just wondering, in an interview, what would you say when they ask you, \"What does it practically mean by Hashtable or Vectors being synchronized?

Answer 1

It means that the access to the underlying array/collection (add, get, set, put, remove, etc..etc..) is all synchronized. It cannot take place simultaneously. Virtually, all access is been laid out in a first-in-first-out (FIFO) queue. Only and if only if there's nobody (read: no other thread) who's currently accessing the object, then the next (thread) in queue may access it.