[Solved] Why does the following code using Iterator next() and remove() throw ConcurrentModificationException? [duplicate]

There is no problem with your usage of Iterator‘s next() and remove(). Your ConcurrentModificationException is caused by adding elements to the List after creating the Iterator. You should add elements to the List before the Iterator is created. Change: Iterator<Integer> iterator = list.iterator(); Collections.addAll(list, 1, 2, 3, 4, 5); to: Collections.addAll(list, 1, 2, 3, 4, … Read more

[Solved] Vector iterators incompatible error for a vector holding iterators of another vector

push_back might cause a reallocation of the data contained in the vector. And that reallocation will make all iterators to the vector invalid. Dereferencing invalid iterators leads to undefined behavior. Indexes into the vector will continue to stay valid, unless you remove elements from the vector. 2 solved Vector iterators incompatible error for a vector … Read more

(Solved) What does the “yield” keyword do?

To understand what yield does, you must understand what generators are. And before you can understand generators, you must understand iterables. Iterables When you create a list, you can read its items one by one. Reading its items one by one is called iteration: >>> mylist = [1, 2, 3] >>> for i in mylist: … Read more