js regex replace code example

Example 1: javascript replace all

const p = 'The quick brown fox jumps over the lazy dog. If the dog reacted, was it really lazy?';

console.log(p.replaceAll('dog', 'monkey'));
// expected output: "The quick brown fox jumps over the lazy monkey. If the monkey reacted, was it really lazy?"

// global flag required when calling replaceAll with regex
const regex = /Dog/ig;
console.log(p.replaceAll(regex, 'ferret'));
// expected output: "The quick brown fox jumps over the lazy ferret. If the ferret reacted, was it really lazy?"

Example 2: javascript replace string

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

Example 3: javascript replace

var res = str.replace("find", "replace");

Example 4: 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 5: replace regex javascript

const p = 'lazy dog. If the dog reacted, was it really lazy?';
const regex = /Dog/ig;
p.replace(regex, 'ferret')
// output: lazy ferret. If the ferret reacted, was it really lazy?

Example 6: javascript regex replace

const search = 'duck'
const replaceWith = 'goose';

const result = 'duck duck go'.replaceAll(search, replaceWith);

result; // => 'goose goose go'