将NSString转换为双倍进行计算,然后再返回以在NSString中打印

Question

我接受NSString为

NSString *value = [valuelist objectAtIndex:valuerow];
NSString *value2 = [valuelist2 objectAtIndex:valuerow2];

来自UIPickerView.我想要

double *cal = value + (value2 * 8) + 3;


NSString *message =[[NSString alloc] initWithFormat:@"%@",cal];

在我对它进行计算之后,我应该能够在消息中获取字符串..请帮助我的程序崩溃

Answer 1

double cal = [value doubleValue] + ([value2 doubleValue] * 8) + 3;
NSString *message =[[NSString alloc] initWithFormat:@"%f",cal];