How to split a string by uppercase and lowercase in JavaScript?

Question

Is it possible to split Strings in JavaScript by case such that the following string below (myString) would be converted into the array (myArray) below:

var myString = "HOWtoDOthis";
var myArray = ["HOW", "to", "DO", "this"];

I have tried the regex below, but it only splits for camelCase:

.match(/[A-Z]*[^A-Z]+/g);

Answer 1

([A-Z]+|[a-z]+). Match all upper case, or all lower case multiple times in capturing groups. Give this a try here: https://regex101.com/r/bC8gO3/1

Answer 2

Another way to do this is to add in a marker and then split using that marker, in this case a double-exclamation point:

JsBin Example

var s = "HOWtoDOthis";

var t = s.replace(/((?:[A-Z]+)|([^A-Z]+))/g, '!!$&').split('!!');