Java List Initialization along with Values Using Guava
This post will introduce various ways to create a Java List using Google Guava library.
Create Mutable List with Values
A mutable list can be modified after we create it, which means we can add, remove, or update its elements.
The Guava way to create a mutable list is quick easy and straightforward
List<Integer> list1 = Lists.newArrayList(1,2,3,4,5); // prefered way
List<Integer> list2 = Lists.newArrayList(Arrays.asList(1,2,3,4,5));
Create Immutable List with Values
An immutable list is read-only, which means any modification such as adding new elements, removing an element, or changing an element is not allowd, it will throw an UnsupportedOperationException if we do this.
ImmutableList.of()
List<Integer> immutableList = ImmutableList.of(1,2,3,4,5); // prefered way
ImmutableList.builder()
List<Integer> immutableList = ImmutableList.<Integer>builder()
.add(1).add(2).add(3).add(4).add(5)
.build();
Create Immutable List from Mutable List
ImmutableList.copyOf()
ImmutableList<Integer> immutableSet = ImmutableList.copyOf(Lists.newArrayList(1,2,3,4,5));
ImmutableList.Builder().addAll()
ImmutableList<Integer> immutableSet = new ImmutableList.Builder<Integer>()
.addAll(Lists.newArrayList(1,2,3,4,5))
.build();