Arraylist and List with Final keyword [duplicate]

Question

Which advantages/disadvantages of making ArrayList (or other Collection) final? And what if we try to do so like:

final List<Integer> A=new ArrayList<Integer>(1,2,3,4,5);
List<Integer> l=new ArrayList<Integer>(4,8,16);
A=l;

Is this is valid? Now the reference A will point to this Array list pointed by l? Please help.

1) final affects the variable, and not the object to which is refers. 2) It is not not allowed to re-assign to a final variable. The compiler should have said as much. — user2864740
– user2864740, Commented Jan 8, 2018 at 21:04
stackoverflow.com/a/10380512/2864740 (this answer is more generalized than the question) , stackoverflow.com/questions/15655012 (specific to final fields, discusses object mutability as well) — user2864740
– user2864740, Commented Jan 8, 2018 at 21:07
Also, ArrayList does not have a constructor that will allow that usage. — Louis Wasserman
– Louis Wasserman, Commented Jan 8, 2018 at 21:09

niemar · Accepted Answer · 2018-01-08 21:05:38Z

1

No, reassignment to final reference is not allowed in Java.

answered Jan 8, 2018 at 21:05

niemar

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