In many places I'm setting modified by, created by etc:
const test = this.state.isValueEdited
? {
modifiedById: getLoggedInUser().userId,
}
: {
// TODO
};
How could I check if getLoggedInUser has some value, than access .userId.. otherwise lets set null.
Thanks
Cheers
Also using the ternary operator
modifiedById: getLoggedInUser() ? getLoggedInUser().userId : null
To avoid executing twice
const evaluation = getLoggedInUser()
{modifiedById: evaluation ? evaluation.userId : null}
getLoggedInUser() twice. Thats inefficient & might cause unwanted sife effects.You can use logical OR ||
modifiedById: ( getLoggedInUser() || { userId: null } ).userId
When the value returned from the getLoggedInUser returns falsy value the {userId : null} will act as default value
This expects value returned from getLoggedUser is falsy value in case it fails the condition
getLoggedInUser() || { userId: null } This means even if userId is null try to access it ? or ?
getLoggedInUser is falsy than only {userId: null} will come into picture, logical OR start evaluating expression from left and stop once it finds true value, if none of the value is true it returns the last value from expression, so here in getLoggedInUser returns falsy value than only the {userId: null} will be used else the value returned from function will be usedYou can retrieve the user first, then you can use the && operator to get the userId only if user returns truthy. false, null, undefined, "", 0, NaN are falsy values
const user = getLoggedInUser() || null;
const test = this.state.isValueEdited ? ({
modifiedById: user && user.userId,
}) : ...
If getLoggedInUser already returns null when the user is not logged, you can omit the || null
