replace only few occurance in a string javascript code example

Example 1: 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"

Example 2: replace all javascript

str.split(search).join(replacement);