replace with and replace by in js code example

Example 1: javascript replace string

var str = "JavaScript replace method test";
var res = str.replace("test", "success");  
//res = Javscript replace method success

Example 2: 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"