const p = 'The quick brown fox jumps over the lazy dog. If the dog reacted, was it really lazy?'; console.log(p.replace('dog', 'monkey')); // expected output: "The quick brown fox jumps over the lazy monkey. If the dog reacted, was it really lazy?" const regex = /Dog/i; console.log(p.replace(regex, 'ferret')); // expected output: "The quick brown fox jumps over the lazy ferret. If the dog reacted, was it really lazy?"