Why is there no need for the concurrent hashmap to lock on read?

Question

Why is there no need for the concurrent hashmap to lock on read?

How does Concurrent Hash Map handle multi-threading during reads?

Answer 1

Any variable(object) at any point of time should be in just one state.Locks are used to prevent assigning multiple states to a variable.

Read operation will never alter the state of the variable, instead it simply fetches the state of the variable (object) at that point of time.