diff --git a/content/dart/concepts/queue/terms/isEmpty/isEmpty.md b/content/dart/concepts/queue/terms/isEmpty/isEmpty.md new file mode 100644 index 00000000000..f78622aadf2 --- /dev/null +++ b/content/dart/concepts/queue/terms/isEmpty/isEmpty.md @@ -0,0 +1,71 @@ +--- +Title: '.isEmpty' +Description: 'Returns true if the queue contains no elements, otherwise returns false.' +Subjects: + - 'Computer Science' + - 'Code Foundations' +Tags: + - 'Dart' + - 'Queues' + - 'Properties' +CatalogContent: + - 'learn-dart' + - 'paths/computer-science' +--- + +In Dart, **`.isEmpty`** is a property used to check whether a `Queue` contains any elements. It returns `true` if the queue has zero elements and `false` if it contains one or more elements. This property is available on the `Queue` class from the `dart:collection` library. + +## Syntax + +```pseudo +queue.isEmpty +``` + +- `queue`: The name of the queue to check for emptiness. + +**Parameters:** + +This property takes no parameters. + +**Return value:** + +The property returns a boolean value: + +- `true` if the queue contains no elements +- `false` if the queue contains one or more elements + +## Example + +This example shows that `.isEmpty` returns `true` for an empty queue and `false` after elements are added: + +```dart +import 'dart:collection'; + +void main() { + Queue values = new Queue(); + + print('Is queue empty? ${values.isEmpty}'); + + values.add(12); + values.add(24); + values.add(36); + + print('Is queue empty? ${values.isEmpty}'); + print('Number of elements: ${values.length}'); + + for(var num in values) { + print(num); + } +} +``` + +The output of this code is: + +```shell +Is queue empty? true +Is queue empty? false +Number of elements: 3 +12 +24 +36 +```