JavaScript String replace

replace swaps one piece of text for another and returns a new string.

By default it only changes the first match.

replaceAll changes every one, which is usually what people expect.

Example

const text = "cat cat cat";

console.log(text.replace("cat", "dog"));

Only the first cat changed.

replace and replaceAll

replace changes the first match only.

replaceAll changes every match.

Both return a new string and leave the original alone.