replace all characters from string javascript code example

Example 1: js replace characters in a string

var str = "Original string!";
var str = str.replace("Original", "New");

Example 2: replace all occurrences of a string in javascript

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"