Javascript's bitwise operators optimization?

Question

Javascript ( along with other languages ) won't evaluate :

• The right side here : imTrue || imFalse
• The right side here : imFalse && imTrue
  etc...

But does those rules are also applies with *bitwise * operations ? ( couldn't find any mdn info)

e.g.

• 1|1 ( would the right side be evaluated here ? )
• 0&1 ( would the right side be evaluated here ? )

Answer 1

The right side in the logical operators you show isn't computed because they're short circuit operators.

There's no such thing for bitwise operators (yes, they're not just boolean operators, they're bitwise operators, which quite changes the problem).

A simple demonstration :

0 & (function(){ return console.log('evaluated'),1 })();

The main reason for short circuit operator isn't performance, it's the ability to avoid errors in such evaluations :

if (a && a.pretty) ...

It's hard to come with the need for short circuit protection when doing bitwise operations.

Note also that the weak typing of javascript makes it hard to evaluate when you don't need the right side. Luaan gives a good example : 1|2.