What is a bitmask and a mask?

Question

On the PHP documentation about JSON it mentions the word bitmask. Wikipedia has it defined as a mask. I don\'t understand either bitmask or mask or how they are useful. Can

Answer 1

In essence, Bitmask is a list of boolean flags (for example isAlive, isMoving, etc) compressed into a single field, usually an integer. It can cut quite a significant amount of JSON string size or memory footprint.

This can be significant especially in PHP where a single boolean in an array can take the same amount of RAM as an integer. There is a very simple Bitmask guide that will explain step by step everything you need to know including how and when to use it.