const regex = /([^,]+)/mg;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('([^,]+)', 'mg')
const str = `1.jpg,2.jpg,3.jpg,4.jpg,5.jpg,6.jpg,7.jpg,8.jpg,9.jpg,10.jpg,11.jpg,12.jpg,13.jpg,14.jpg,15.jpg,16.jpg,17.jpg,18.jpg,19.jpg,20.jpg,21.jpg,22.jpg,23.jpg,24.jpg,25.jpg,26.jpg,27.jpg,28.jpg,29.jpg,30.jpg,31.jpg,32.jpg,33.jpg,34.jpg,35.jpg,36.jpg,37.jpg,38.jpg,39.jpg,40.jpg,41.jpg,42.jpg,43.jpg,44.jpg,45.jpg,46.jpg,47.jpg,48.jpg,49.jpg,50.jpg,51.jpg,52.jpg,53.jpg,54.jpg,55.jpg,56.jpg,57.jpg,58.jpg,59.jpg,60.jpg`;
const subst = `mysite.com/tripoli/$1`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions