JSFiddle - React, Tailwind, and code Playground

JavaScript

var res, text = "ABC",
    regexp = /\b[A][B]\b|\b[A][C]\b/g;


while (regexp.test(text)) {
    res = regexp.exec(text);   
    console.log("regexp.lastIndex:", regexp.lastIndex, 
                "index:", res.index,
                "res[0]:", res[0],
                "res[1]:", res[1]);
}