Nullish Coalescing Operator Summary

TODO: collapasable, copyable, download, etc

What does ?? mean in this expression? const [stagedQuery, setStagedQuery] = useAtom( query ?? getDefaultQuery(chatTimeRange), );In the JavaScript expression you've provided, ?? is the nullish coalescing operator. It is used to return the right-hand operand when the left-hand operand is null or undefined, otherwise the left-hand operand is returned. It's a way to provide a default value when a variable might be null or undefined.

In your specific code snippet:

const [stagedQuery, setStagedQuery] = useAtom<Query>(
    query ?? getDefaultQuery(chatTimeRange),
);

The query ?? getDefaultQuery(chatTimeRange) means that if query is null or undefined, then getDefaultQuery(chatTimeRange) will be called and its return value will be used. Otherwise, query will be used as the value. This is used here to initialize the stagedQuery state with either the existing query or a default query obtained by calling getDefaultQuery(chatTimeRange).

Nullish Coalescing Operator Summary created at Tue Jan 20 1970 20:18:13 GMT+0000 (Coordinated Universal Time)