Type Casting & Coercion: Bitshifting both bad and good?

[wildlyinaccurate]

In the Type Casting & Coercion section, you've got the following:

// bad
var val = inputValue >> 0;

// good
/**
 * parseInt was the reason my code was slow.
 * Bitshifting the String to coerce it to a
 * Number made it a lot faster.
 */
var val = inputValue >> 0;

Can you clarify whether bitshifting is good or bad?

[op1ekun]

In my opinion using bit shifitng for coercing to number is like using JSON.stringify for casting to String (instead of using toString). It's not evil, but it should be used only if necessary like in the provided example.

[ssorallen]

The example could use more explanation. The second example is marked with a // good because it is commented explaining why bitshifting was used instead of the preferred parseInt. The first is "bad" because it is an uncommented use of bitshifting.

If you are parsing numbers from strings, parseInt and parseFloat are preferred because their functionality is explicit.

[dcerri]

I miss you ross!

[ssorallen]

@dcerri 🍻

[hshoff]

This one of those cases where I didn't consider casual scanning..I can see the confusion. Above the example code it says:

If for whatever reason you are doing something wild and parseInt is your bottleneck and need to use Bitshift for performance reasons, leave a comment explaining why and what you're doing.

I'll move it for clarity.