Question

Is there any reason for Scala not support the ++ operator to increment primitive types by default?
For example, you can not write:

var i=0
i++

Thanks

Answer 1

My guess is this was omitted because it would only work for mutable variables, and it would not make sense for immutable values. Perhaps it was decided that the ++ operator doesn’t scream assignment, so including it may lead to mistakes with regard to whether or not you are mutating the variable.

I feel that something like this is safe to do (on one line):

i++

but this would be a bad practice (in any language):

var x = i++

You don’t want to mix assignment statements and side effects/mutation.