Question

I want a count on an array where a sub array meets a condition.
I thought I could do this, but I can’t.

NSLog(@"%d",[[_sections enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            [[obj objectAtIndex:4] isEqualToString:@"1"];
        }] count]);

Answer 1

enumerateObjectsUsingBlock: doesn’t return anything. I’d bet that code won’t even compile (and, as your comment states, auto-completion doesn’t work — and it shouldn’t).

Use NSArray’s indexesOfObjectsPassingTest:
and take the count of the resulting NSIndexSet.

Documented here.