How to dynamically create regex to use in .match Javascript?

RegExp is your friend:

var p = "\\*\\|", s = "\\|\\*"

var reg = new RegExp(p + '(\\d{3,})' + s, 'g')

"*|1387461375|* hello *|sfa|* *|3135145|* test".match(reg)

The key to making the dynamic regex global is to transform it into a RegExp object, and pass 'g' in as the second argument.

Working example.