Java - Exception in thread “main” java.util.ConcurrentModificationException

Question

Is there any way I can modify the HashMap values of a particular key while iterating over it?

A sample program is given below:

public st         


        

Answer 1

Concurrent Modification in programming means to modify an object concurrently when another task is already running over it. Fail Fast And Fail Safe Iterators in Java Iterators in java are used to iterate over the Collection objects. Fail-Fast iterators immediately throw ConcurrentModificationException if there is structural modification of the collection. Fail-Safe iterators don’t throw any exceptions if a collection is structurally modified while iterating over it. This is because, they operate on the clone of the collection, not on the original collection and that’s why they are called fail-safe iterators. Please use ConcurrentHashMap if you want to modify in between.