how to replace something in javascript code example

Example 1: 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"

Example 2: javascript string replace

const p = 'Its going to rain today and its going to rain tomorrow';

// Example of replacing all occurrances

// g = global search, which searches all instances
// i = case insensitive, which will match 'a' with 'A'
const regex = /rain/gi;
console.log(p.replace(regex, 'snow'));
// expected output: "Its going to snow today and its going to snow tomorrow"

// Example of replacing the first occurance
console.log(p.replace('rain', 'snow'));
// expected output: "Its going to snow today and its going to rain tomorrow"