oc 小数乘法,并取整
oc的double,float类型无法满足小数乘法的需求
只能用NSDecimalNumber实现
NSDecimalNumberHandler *roundingBehavior = [NSDecimalNumberHandler decimalNumberHandlerWithRoundingMode:NSRoundDown scale:0 raiseOnExactness:NO raiseOnOverflow:NO raiseOnUnderflow:NO raiseOnDivideByZero:YES]; NSDecimalNumber *a = [[NSDecimalNumber alloc]initWithString:@"0.8"]; NSDecimalNumber *b = [[NSDecimalNumber alloc]initWithString:@"0.6"]; //相乘并取整 NSDecimalNumber *c = [a decimalNumberByMultiplyingBy:b withBehavior:roundingBehavior];