Nullish coalescing
Widely available since 2023-03-16
The nullish coalescing (??) and nullish coalescing assignment (??=) operators return (or assign) its right-hand side operand when its left-hand side operand is null or undefined, and otherwise returns its left-hand side operand.
Learning resources on MDN
Browser support
- Chrome 85 Released on 2020-08-25
- Chrome Android 85 Released on 2020-08-25
- Edge 85 Released on 2020-08-27
- Firefox 79 Released on 2020-07-28
- Firefox for Android 79 Released on 2020-07-28
- Safari 14 Released on 2020-09-16
- Safari on iOS 14 Released on 2020-09-16
Specifications
- ECMAScript Language Specification (#prod-CoalesceExpression), from TC39 (Ecma International).