OBJ-C-如果语句被跳过？

Question

I have a block of code inside of a button that contains various if statements. All work except my last one,

if (usercurrentPoints < hoursCalculated ) {

This if statement seems to be skipped, and I'm not sure why (I tried to cut this code down as much as possible)? Eg if points is greater than currentuserPoints, an alert should pop up. However it bypasses this, and just saves my data anyway (thus, sending my user into a negative point balance). Any help is appreciated!

- (IBAction)sendMessage:(id)sender {

        NSInteger hour = [components hour];
        NSInteger minute = [components minute];

        NSString *points;

        if (hour <= 1) {

            points = @"1";


        } else if (hour > 1 && hour < 9) {

            points = @"9";


        } else if (hour <= 9) {

            points = @"9";

        } else if (hour > 9 && hour <= 24) {

            points = @"24";


        } else if (hour > 24 && hour <= 48) {

            points = @"48";

        } else if (hour > 48 && hour <= 72) {

            points = @"72";

        } else if (hour > 72 && hour <= 96) {

            points = @"96";

        } else if (hour > 96) {

            points = @"96";

            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Uh Oh!"
                                                            message:@"Requests cannot exceed 5 days. Please create separate requests."
                                                           delegate:self
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];




           self.sendMessage.enabled = NO;



            return;


        }






        NSDictionary *swapValues = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:points, nil] forKeys:[NSArray arrayWithObjects:@"value", nil]];
        NSDictionary *totalPoints = [NSDictionary dictionaryWithObject:[NSArray arrayWithObject:swapValues] forKey:@"und"];

        [nodeData setObject:totalPoints forKey:@"field_swapvalue"];



        NSDictionary *enddateValues = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:formattedendDate, nil] forKeys:[NSArray arrayWithObjects:@"value", nil]];

        NSDictionary *finalendDate = [NSDictionary dictionaryWithObject:[NSArray arrayWithObject:enddateValues] forKey:@"und"];

      [nodeData setObject:finalendDate forKey:@"field_endswaptime"];


        NSDictionary *swapInitiated = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"Requested", nil] forKeys:[NSArray arrayWithObjects:@"value", nil]];
        NSDictionary *swapRequest = [NSDictionary dictionaryWithObject:[NSArray arrayWithObject:swapInitiated] forKey:@"und"];

        [nodeData setObject:swapRequest forKey:@"field_swapaccepted"];


        NSString *hoursCalculated = points;

            NSString *usercurrentPoints = [[[DIOSSession sharedSession] user] objectForKey:@"field_points_balance"][@"und"][0][@"value"];
        NSLog(@"USERS CURRENT BALANCE %@", usercurrentPoints);

[usercurrentPoints intValue];
[hoursCalculated intValue];


     if (usercurrentPoints < hoursCalculated ) {
            NSLog(@"CALCULATED %@", hoursCalculated);


            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Uh Oh!"
                                                            message:@"You don't have enough hours to complete this."
                                                           delegate:self
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];




        } else  {


            int result = [usercurrentPoints intValue] - [points intValue];


            NSString *resultPoints = [NSString stringWithFormat:@"%d", result];


            NSMutableDictionary *userData = [NSMutableDictionary new];


            NSDictionary *targetPoints = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects: resultPoints, nil] forKeys:[NSArray arrayWithObjects:@"value", nil]];
            NSDictionary *finalPoints = [NSDictionary dictionaryWithObject:[NSArray arrayWithObject:targetPoints] forKey:@"und"];

            [userData setObject:finalPoints forKey:@"field_points_balance"];

Answer 1

PROBLEM:

Using < or > with strings does weird stuff. It certainly won't do what you want consistently.

MINIMAL CODE CHANGE SOLUTION:

[usercurrentPoints intValue] by itself does nothing meaningful. Since you only need to fix the comparison, change it to if ([usercurrentPoints intValue] < [hoursCalculated intValue]) .

BETTER SOLUTION:

Use the correct data type for the value. points and hoursCalculated are only ever used as integers, so there's no reason to define them as strings. I'm not familiar with DIOSSession, but I don't see why you couldn't assign the intValue to an int variable instead.

Answer 2

You are comparing two pointers not the value and the result depends on the relative locations in the address space of the objects pointed to.

less-than-comparison-for-void-pointers might help you for better understanding.