How do we change a struct value that has been passed in a method?

Question

I want to pass a struct within a method so i can change it's value within, but I am not too sure on it's syntax:

 struct qsTracker {
          int points;
          BOOL flagged;
 } myCurrentQs;

[self calculateScore:myCurentQs];

-(void) calculateScore:(struct qsTracker) currentQs  {
    currentQs.points++;
    currentQS.flagged = YES;
}

Obviously, currentQs doesn't see any changes. any help would be much appreciated.

Answer 1

You should pass in a pointer to the struct, instead of the struct itself:

-(void) calculateScore:(struct qsTracker *) currentQs  {
    currentQs->points++;
    currentQS->flagged = YES;
}

And then:

[self calculateScore:&myCurentQs];

Because currentQs is now a pointer, changes made inside the method will be reflected outside the method.