Comparing NSNumbers in Objective C

objective-c nsnumber
Doug Molineux picture Doug Molineux · Jul 7, 2011 · Viewed 47.1k times · Source

I am a beginner at Objective-C and I am a bit confused at this scenario. I have the following code:

if (number1 < number2) {
    NSLog(@"THE FOLLOWING NUMBER ");
    NSLog(@"%@", number1);
    NSLog(@"IS LESS THAN");
    NSLog(@"%@", number2);
}

When I run this code I see really strange results like this:

2011-07-06 20:38:18.044 helloworld[1014:207] THE FOLLOWING NUMBER 
2011-07-06 20:38:18.047 helloworld[1014:207] 190.8776
2011-07-06 20:38:18.050 helloworld[1014:207] IS LESS THAN
2011-07-06 20:38:18.053 helloworld[1014:207] 96.75866

Both numbers are NSNumber objects, how could something like this happen? I am getting the two numbers by finding distances between sprites on the screen.

Any clues or advice would really be appreciated

Answer

Kal picture Kal · Jul 7, 2011

I assume number1 and number2 are pointers to objects. The < sign is comparing the pointers.

You need to compare the actual floatValue or doubleValue 

if ([number1 doubleValue] < [number2 doubleValue])

....

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