Demonstration of Collections.unmodifiableList method

Collections.unmodifiableList

jshell> List<String> list = new ArrayList<String>();
list ==> []

jshell> list.add("Smart");
$2 ==> true

jshell> list.add("Techie");
$3 ==> true

jshell> System.out.println("The list values are: "+ list);
The list values are: [Smart, Techie]

jshell> // make the list unmodifiable

jshell>    List<String> immutablelist = Collections.unmodifiableList(list);
immutablelist ==> [Smart, Techie]

jshell> // try to modify the list

jshell>    immutablelist.add("Smart_1");
|  java.lang.UnsupportedOperationException thrown:
|        at Collections$UnmodifiableCollection.add (Collections.java:1056)
|        at (#6:1)

jshell>