I am looking to validate an input text against the following pattern in JS/JQuery:
var isMatch = inputText.match([PR]-\d+-[A-Z]+\d+)
You just need to add group to your regex.
var match = inputText.match(/^[PR]-\d+-[A-Z]+(\d+)$/);
If match is not null, then number will be in array on position
var number = match ? match : null;
EDIT: Added anchors as Aaron suggested.