JSFiddle - React, Tailwind, and code Playground

JavaScript

var string = "12.0,34.0";
var re = new RegExp(/[-+]?([1-8]?\d(\.\d+)?|90(\.0+)?),\s*[-+]?(180(\.0+)?|((1[0-7]\d)|([1-9]?\d))(\.\d+))?/);
if (re.test(string)) {
  alert("Valida");
} else {
  alert("Invalida");
}