Convert Set to List without creating new List
To convert a Set
to a List
in Java without creating a new List
object, you can use the List
constructor that takes a Collection
as an argument.
For example, given a Set
called set
, you can create a List
that contains the same elements as the Set
using the following code:
List<String> list = new ArrayList<>(set);
This creates a new ArrayList object that is initialized with the elements of the Set
.
Note that this method does not create a new copy of the Set
; it simply creates a new List
object that is backed by the same elements as the Set
. This means that if you modify the List
, the changes will be reflected in the Set
, and vice versa.
Here is an example of how you can use this method to convert a Set
to a List
and then modify the List
:
Set<String> set = new HashSet<>();
set.add("apple");
set.add("banana");
set.add("cherry");
List<String> list = new ArrayList<>(set);
list.add("date");
System.out.println(set); // prints [apple, banana, cherry, date]
System.out.println(list); // prints [apple, banana, cherry, date]
In this example, the List
and the Set
both contain the same elements, and modifying one of them also modifies the other.