Convert String with Dot or Comma as decimal separator to number in JavaScript

Question

An input element contains numbers a where comma or dot is used as decimal separator and space may be used to group thousands like this:

\'1,2\'

Answer 1

Here is my solution that doesn't have any dependencies:

return value
  .replace(/[^\d\-.,]/g, "")   // Basic sanitization. Allows '-' for negative numbers.
  .replace(",", ".")           // Change all commas to periods.
  .replace(/\.(?=.*\.)/g, ""); // Remove all periods except the last one.

(I left out the conversion to a number - that's probably just a parseFloat call if you don't care about JavaScript's precision problems with floats.)

The code assumes that:

• Only commas and periods are used as decimal separators. (I'm not sure if locales exist that use other ones.)
• The decimal part of the string does not use any separators.