Search Terms

Nullish coalescing assignment

Suggestion

A new operator ??= to assign some default to a variable/property if it is nullish.

It's also avaibale in PHP: https://wiki.php.net/rfc/null_coalesce_equal_operator

Examples

obj1.obj2.obj3.x ??= 42;
instead of
obj1.obj2.obj3.x = obj1.obj2.obj3.x ?? 42;

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.