JSFiddle - React, Tailwind, and code Playground

JavaScript

function RegExpStatePersistenceTest() {
    var regex =/[a-z]/g;

    regex.counter = regex.counter || 0;
    regex.counter++;
    
    console.log("counter:" + regex.counter);
}

RegExpStatePersistenceTest();
RegExpStatePersistenceTest();
RegExpStatePersistenceTest();
RegExpStatePersistenceTest();