In JavaScript, we can’t replace the all occurance of substring in a string without use of global regex. In our previous post that is Replace all instances of a string in JavaScript we have shown how to replace with regex.

Now the JavaScript propose the new method String.prototype.replaceAll. This gives the straight-forward way to replace all the instance of substring.

Syntax

String.prototype.replaceAll(searchValue, replaceValue)

let str = '🍬🍭🍬🍭🍬🍭';
console.log(str.replace('🍭', '🍰'));
//🍬🍰🍬🍭🍬🍭
console.log(str.replaceAll('🍭', '🍰'));
//🍬🍰🍬🍰🍬🍰

When using a regular expression search value, it must be global.

'aabbcc'.replaceAll(/b/, '.');
//TypeError: replaceAll must be called with a global RegExp ☹️

'aabbcc'.replaceAll(/b/g, '.'); //aa..cc 😊

What happens if searchValue is the empty string?

'⚽'.replace('', '_');
// → '_⚽'
'⚽⚽⚽'.replace(/(?:)/g, '_');
// → '_⚽_⚽_⚽_'
'⚽⚽⚽'.replaceAll('', '_');
// → '_⚽_⚽_⚽_'

Resource

• MDN web docs
• tc39/proposal-string-replaceall: ECMAScript proposal … – GitHub

Happy Learning ✌️