Comparing NSNumbers in Objective C
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])
....
For cases where you simply want to test whether two NSNumber properties hold the same value, then from the Apple documentation it seems that using
- (BOOL)isEqualToNumber:(NSNumber *)aNumber
is the most straightforward and efficient way to compare two NSNumber values.
For example:
if ([someNumber isEqualToNumber:someOtherNumber])
{
// The numbers hold the same value
}
else
{
// The numbers hold different values
}
The documentation also says "This method is more efficient than compare: if you know the two objects are numbers."
Whenever you need to know whether a value is smaller or greater, they offer the
- (NSComparisonResult)compare:(NSNumber *)aNumber
method, but personally I would prefer at that point to just pull out the integer values (or double values) and use regular < and > operators to do the comparison, because that makes the code much easier to read, like so:
if (firstNumber.intValue > secondNumber.intValue)
{
// First number is greater than the second number
}
else if (firstNumber.intValue == secondNumber.intValue)
{
// The two numbers have the same value
}
else
{
// The first number is smaller than the second number
}
Something like that is much easier to read than calls to -compare:, in my opinion.
Erik
NSNumber has a method for comparison: - (NSComparisonResult)compare:(NSNumber*)aNumber
if([numberOne compare:numberTwo] == NSOrderedSame)
{
// proceed
}