我正在研究一种在Objective-C中平均任意多个数字的方法，这是我迄今为止的方法：
-(double)average:(double)num, ...
{
va_list args;
va_start(args, num);
double currentAverage = num;
long long timesAveraged = 1;
for(double d in args)
currentAverage = ((currentAverage * timesAveraged) + d) / ++timesAveraged;//Error occurs on this line
return currentAverage;
}
但是，当我编译它时，我收到一个错误，指出“ Selector element does not have a valid object type”，所以我的第一个解决方案是将方法更改为以下内容：
-(double)average:(double)num, ...
{
va_list args;
va_start(args, num);
double currentAverage = num;
long long timesAveraged = 1;
for(NSNumber *d in args)
currentAverage = ((currentAverage * timesAveraged) + [d doubleValue]) / ++timesAveraged;//Error occurs on this line
return currentAverage;
}
但是，现在它给了我一个令人不安的类似错误“ Expression does not have a valid object type”。
我显然做错了。关于如何正确执行此操作的任何建议？
解决方案
我已经能够通过编写这样的方法来编译文件：
-(double)average:(double)num, ...
{
va_list args;
va_start(args, num);
double currentAverage = num;
long long timesAveraged = 1;
for (NSNumber *arg = [NSNumber numberWithDouble:num]; arg != nil; arg = va_arg(args, NSNumber*))
{
currentAverage = ((currentAverage * timesAveraged) + [arg doubleValue]) / ++timesAveraged;
}
va_end(args);
return currentAverage;
}