Populate Height from HealthKit

PopulateHeight.m

HKQuantityType *heightType = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeight];
    
// Since we are interested in retrieving the user's latest sample
// we sort the samples in descending order by end date
// and set the limit to 1
NSSortDescriptor *timeSortDescriptor = [[NSSortDescriptor alloc] initWithKey:HKSampleSortIdentifierEndDate ascending:NO];

// construct the query & since we are not filtering the data the predicate is set to nil
HKSampleQuery *query = [[HKSampleQuery alloc] initWithSampleType:heightType predicate:nil limit:1 sortDescriptors:@[timeSortDescriptor] resultsHandler:^(HKSampleQuery *query, NSArray *results, NSError *error) {

	// if there is a data point, dispatch to the main queue
    if (results) {
        dispatch_async(dispatch_get_main_queue(), ^{
            HKQuantitySample *quantitySample = results.firstObject;
            
            // pull out the quantity from the sample
            HKQuantity *quantity = quantitySample.quantity;
            
            HKUnit *heightUnit = [HKUnit inchUnit];
            double usersHeight = [quantity doubleValueForUnit:heightUnit];
            _txtHeight.text = [NSString stringWithFormat:@"%@ in", [NSNumberFormatter localizedStringFromNumber:@(usersHeight) numberStyle:NSNumberFormatterNoStyle]];
        });
    }
}];

// do not forget to execute the query after its constructed
[_healthStore executeQuery:query];