Programming Groovy 2

Iterating Over an ArrayList

We often navigate or iterate over a list of values. Groovy provides elegant ways to iterate, and to perform operations on the values as we iterate over lists.

Using List’s each Method

As we saw in Chapter 4, ​Using Closures​, Groovy provides convenient ways to iterate collections. This iterator, the method named each, is also known as an internal iterator. For more information, see ​Internal vs. External Iterators​.

Internal vs. External Iterators

We’re used to external iterators in languages like C++ and Java. These iterators allow their user or client to control the iteration. We have to check whether we’re at the end of iteration and explicitly move to the next element.

Internal iterators are popular in languages ...