I have a Regex for validation input type="number" but the problem with my regex that it allows to enter plus character, how to prevent enter plus symbol, but allow to enter minus? For example you can enter: 123; 11,22; -33; -33.44 but not allowed enter 123 and -0, 0

const deprecatedKeys = /^- ?\D$|^decimal$|^multiply$|^add$|^divide$|^subtract$|^spacebar$/i;

CodePudding user response：

The 1st part of your current pattern is problematic: ^- ?\D$ would currently match an hyphen between one and unlimited times but as few as possible and a non-digit character. So stuff like '----- ' or '-X' would match too.

If you want to allow for an optional leading hyphen and optional decimals, you could use:

^(?!-0$)-?\d (?:[.,]\d )?$

Furthermore, all these alternations could be grouped in a non-capture group with a single leading and trailing anchor:

^(?:(?!-0$)-?\d (?:[.,]\d )?|decimal|multiply|add|divide|subtract|spacebar)$