how to select and replace words in a string javascript code example

Example 1: javascript replace all occurrences of string

function replaceAll(str, find, replace) {
    var escapedFind=find.replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
    return str.replace(new RegExp(escapedFind, 'g'), replace);
}
//usage example
var sentence="How many shots did Bill take last night? That Bill is so crazy!";
var blameSusan=replaceAll(sentence,"Bill","Susan");

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"

Example 3: 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"