Combining regular expressions in Javascript

Question

Is it possible to combine regular expressions in javascript.

For ex:

 var lower = /[a-z]/;
 var upper = /[A-Z]/;
 var alpha = upper|lower;//Is this          


        

Answer 1

Based on Bry6n answer here's a solution I use:

const Regexes = {
  Empty: /^$/,
  Minus: /^[-]$/,
  DotAndNumber: /^\.\d+$/,
  NumberAndDot: /^\d+\.$/,
  Float: /^[-]?\d+(\.\d+)?$/,
};

const orRegex = (...regexes) =>
  new RegExp(regexes.map(r => r.source).join('|'));

const FloatInputRegex = orRegex(
  Regexes.Empty,
  Regexes.Minus,
  Regexes.DotAndNumber,
  Regexes.NumberAndDot,
  Regexes.Float,
);