链式编程的计算工具类
#import "MCCalculation.h"
//方式一
self.mcCalculation = [[MCCalculation alloc] init];
NSDecimalNumber* decimalNumber1 = self.mcCalculation.start(@"1").adding(@2).multiplyingBy(@"3").result;
NSLog(@"decimalNumber1 =%@",decimalNumber1.stringValue);
//方式二
self.mcCalculation.start(@"2");
self.mcCalculation.adding(@3);
self.mcCalculation.multiplyingBy(@4);
NSDecimalNumber* decimalNumber2 = self.mcCalculation.result;
NSLog(@"decimalNumber2 =%@",decimalNumber2.stringValue);