简单的Objective-C程序不工作

Question

int main (int argc, const char * argv[])
{

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    int n, number, triangularNumber;
    NSLog(@"What Triangular Number Do You Want?");
    scanf(@"%i", &number);
    triangularNumber = 0;

    for (n = 1; n <= number; ++n)  
        triangularNumber += n;
        NSLog(@"Triangular Number %i is %i", number, triangularNumber);

    [pool drain];
    return 0;
}

当我写一个整数时，输出如下：

Triangular Number 0 is 0

Answer 1

您的输入数字是0，而for循环中的条件从1开始。因此，该循环永远不会执行。

Answer 2

它应该是：

for (n = 1; n <= number; ++n)  {
        triangularNumber += n;
        NSLog(@"Triangular Number %i is %i", number, triangularNumber);
}

按照您编写它的方式，它被解析为：

for (n = 1; n <= number; ++n)  {
    triangularNumber += n;
}
NSLog(@"Triangular Number %i is %i", number, triangularNumber);

由于输入(number)为0(如print所示)，因此不会发生循环，但仍会打印该行。