On: John Carmack on mutable variables

[ErroneousBosh]

But that's just it, why would a copy ever happen? Why would you want a correct and an incorrect version of your variable hanging about?

[kubanczyk → ErroneousBosh]

Taking your point of view: you assigned a value1 to a name. Then you assigned a value2 to the same name.

You say that value2 is correct. It logically follows that value1 was incorrect. Why did you assign it then?

The names are free, you can just use a correct name every single time.

[zaphirplane → kubanczyk]

Because the account owner withdrew money . The player scored a goal, the month ticked over, the rain started, the car accelerated, a new comment was added to the thread .

The world by definition mutates over time.

[kubanczyk → zaphirplane]

Ah, true. If the var is a part of a long-living state, all good. That's just rarely seen in CRUD apps, more common in games.