Question about arithmetic solution

Hi,

My question is about M121 (Mongo university) Chapter 2: Basic Aggregation - Utility Stages / Lab - Bringing it all together

Why is the more verbose aggregation expression such as {$add: [1, "$field"]} preferred over the simpler 1 + $field ?

This is to keep everything a JSON object.

So we decrease readability to increase json size ?

There must be an other reason.

One reason to keep it as JSON that I use is that you I store my aggregations in a MongoDB database. This is some kind of library that is very easy to distribute and reuse.