Groovy Goodness: Removing the Last Item From Lists [Snippet]
Ready to get Groovy? This code snippet looks at Groovy 2.5.0 and its different List and pop methods. Enjoy!
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Versions of Groovy before 2.5.0 implemented different methods for the
List class for the items at the end of a
List object. The
pop method removed the last item of a
List and the
push method added an item to the
List. Groovy 2.5.0 reimplemented these methods so that they now work on the first item of a
List instance. To remove an item from the end of the
List we can use the newly added method
In the following sample Groovy code, we use the
add methods to remove and add items to the end of the list. With the
push methods, we can remove and add items to the beginning of the
def list = ['Groovy', 'is', 'great!'] // Remove last item from list // with removeLast(). assert list.removeLast() == 'great!' assert list == ['Groovy', 'is'] // Remove last item which is now 'is'. list.removeLast() // Add new item to end of the list. list.add 'rocks!' assert list.join(' ') == 'Groovy rocks!' /* IMPORTANT */ /* pop() and push() implementations has changed */ /* in Groovy 2.5.0. They now work on the first */ /* item in a List instead of the last. */ // Using pop() we remove the first item // of a List. assert list.pop() == 'Groovy' // And with push we add item to // beginning of a List. list.push 'Spock' assert list.join(' ') == 'Spock rocks!'
Written with Groovy 2.5.0.
Published at DZone with permission of Hubert Klein Ikkink, DZone MVB. See the original article here.
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