14.4 Implementing the java.lang.Comparable<E> Interface In order to sort the objects of a class, it should be possible to compare the objects. A total ordering allows objects to be compared. [...]
Iterating Over a Collection A common operation on a collection is to iterate over all elements in a collection in order to perform a particular operation on each individual element. [...]
Using the forEachRemaining() Method A convenient way to perform a task on each element of a collection is to use the forEachRemaining() method of the Iterator<E> interface. This method requires [...]
15.2 Collections The Collection<E> interface specifies the contract that all collections should implement. Some of the operations in the interface are optional, meaning that a collection may choose to provide [...]
Using an Explicit Iterator on a Collection A collection provides an iterator which allows sequential access to the elements of a collection. An iterator can be obtained by calling the [...]
Cast Expressions The context of a cast expression can provide the target type for a lambda expression or a method reference. In the two statements below, the cast provides the [...]
Using the forEach() Method to Iterate Over a Collection The default method forEach() of the Iterable<E> interface (which the Collection<E> interface implements) allows us to do away with an explicit [...]
Using the removeIf() Method to Filter a Collection The following default method of the Collection<E> interface makes the task of filtering a collection much easier, as no explicit iteration is [...]
Array Operations The following operations convert collections to arrays. See also array operations on array lists (ยง12.6, p. 658). Object[] toArray()<T> T[] toArray(T[] a) The first toArray() method returns an [...]
A compareTo() method is seldom implemented to interoperate with objects of other classes. For example, this is the case for primitive wrapper classes and the String class. The calls to [...]