NSNumber::比較大小

NSNumber compare

!!! 切記！儲存於NSNumber物件的值，擷取時必須要一致。
擷取時輸出型態與儲存時的型態不同時，系統並不會出錯，而會輸出無效的值

        NSNumber        *myNumber, *floatNumber, *intNumber;
        NSInteger       myInt;
        NSComparisonResult compareResult1, compareResult2;

        intNumber = [NSNumber numberWithInteger: 100];
        floatNumber = [NSNumber numberWithFloat: 100.00];
        myNumber = [NSNumber numberWithDouble: 123456e+15];
        
        compareResult1 = [intNumber compare: myNumber];
        compareResult2 = [intNumber compare: floatNumber];
        //NSOrderedAscending    <  官方解釋(The left operand is smaller than the right operand.)
        //NSOrderedSame        ==  官方解釋(The two operands are equal.)
        //NSOrderedDescending   >  官方解釋(The left operand is greater than the right operand.)
        if(compareResult1 == NSOrderedAscending)
            NSLog(@"intNumber is less than myNumber");
        else if(compareResult1 == NSOrderedSame)
            NSLog(@"intNumber is equal to myNumber");
        else if(compareResult1 == NSOrderedDescending)
            NSLog(@"intNumber is greater than myNumber");
        else
            NSLog(@"What the fuck?!");

        if(compareResult1 == NSOrderedAscending)
            NSLog(@"intNumber is less than floatNumber");
        else if(compareResult1 == NSOrderedSame)
            NSLog(@"intNumber is equal to floatNumber");
        else if(compareResult1 == NSOrderedDescending)
            NSLog(@"intNumber is greater than floatNumber");
        else
            NSLog(@"What the fuck?!");

執行結果：