Numbers should be allowed to contain underscores

[gcxfd]

how to remove the space add before underline ?

const _list = 0b1111_0110;
->

const _list = 0b1111 _0110;

break my code

[bitwiseman]

@gcxfd
0b indicates a binary number, which cannot contain underscores. What are you trying to achieve with that code?

[gcxfd]

see the screen shot , it can contains _

[gcxfd]

0xFFFF_1234 is ok too

[bitwiseman]

Ah, I see. Relatively new feature - numeric separator.
https://github.com/tc39/proposal-numeric-separator

Someone just needs to add _ as a valid numeral inside numbers along with a few tests. Would be a good first issue.

https://github.com/beautify-web/js-beautify/blob/5c00e1d7ec2be058c1c652958bca24e38a1699af/js/src/javascript/tokenizer.js#L69

https://github.com/beautify-web/js-beautify/blob/5c00e1d7ec2be058c1c652958bca24e38a1699af/python/jsbeautifier/javascript/tokenizer.py#L64-L66