java:17: error: local variables referenced from a lambda expression must be final or effectively final count ++ ;
Modifying variables inside java lambdas. Integer list[] = {1,2,3,4,5,6,7,8}; int index = 0; Arrays.asList(list).forEach(e -> { System.out.println(e+" at index "+index); index++; }); Error : maze2.java:22: error: local variables referenced from a lambda expression must be final or effectively final System.out.println(e+" at index "+index); ^ maze2.java:23: error: local variables referenced from a lambda expression must be final or effectively final index++; ^ Solution : Integer list[] = {1,2,3,4,5,6,7,8}; int[] index = {0}; Arrays.asList(list).forEach(e -> { System.out.println(e+" at index "+index[0]); index[0]++; }); Output : 1 at index 0 2 at index 1 3 at index 2 4 at index 3 5 at index 4 6 at index 5 7 at index 6 8 at index 7