JS: Efficient way to convert Integer to 8 digit binary?

Question

I know this can be accomplished in different ways, and there are already some example implementations suggested in other answers.

So what I'm asking is what is the most efficient in terms of computing way to do it.

Self explanatory:

var num = 3;

console.log(num.toString(2));

//Outputs:   "11"

//Desired output:   "00000011";

Thank you.

Please note that I specified the 8 digit notation. – ferret96 Oct 07 '14 at 18:39 — ferret96, Oct 07 '14 at 18:39

Romeo · Answer 1 · 2014-10-07T18:57:24.067

6

Try this

console.log(("00000000"+num.toString(2)).substr(-8));

Or as @LcSalazar stated:

console.log(("00000000"+num.toString(2)).slice(-8));

edited Oct 07 '14 at 18:57

answered Oct 07 '14 at 18:39

Romeo

I already have. I get outputs that range from 8 to 12 digits. – ferret96 Oct 07 '14 at 18:42
2

It's impossible, `substr(-8)` returns the last 8 digits of the string. – Romeo Oct 07 '14 at 18:43
You're right. I had a parenthesis balancing mistake. Thank you. – ferret96 Oct 07 '14 at 18:52
1

@ferret96 - A note: You might want to consider using `.slice()` instead. IE doesn't work well with `.substr()` – LcSalazar Oct 07 '14 at 18:55
Or that, I come from a PHP background. – Romeo Oct 07 '14 at 18:56

1 Answers1