change value of variable in forEach loop java 8 [duplicate]

Question

int count =0;
requestUserDto.getNodeIds().forEach(userNodeId->{
    count++; // this statement shows error
     // some another statements here
    }
});

why count++ shows error

Error:

Local variable i defined in an enclosing scope must be final or effectively final

Answer 1

Considering lambdas are essentially syntactic sugar for an anonymous inner class, a variable used in a lambda expression must be effectively final. Check out this post for more details.