javascript replace
const p = 'dog dog cat rat';
const regex = /dog/gi;
console.log(p.replace(regex, 'cow'));
//if pattern is regular expression all matches will be replaced
//output: "cow cow cat rat"
console.log(p.replace('dog', 'cow'));
// If pattern is a string, only the first occurrence will be replaced.
//output: "cow dog cat rat"