使用#define时产生奇怪的mod运算符(%)

Question

int temp1,temp2,temp3;
temp1 = 199;
temp2 = 200;
temp3 = 199%temp2;

CString txt;
txt.Format(_T("temp3 = %d"),temp3);
AfxMessageBox(txt);

按预期输出199.

#define WIDTH 100
#define BUFFERWIDTH 200
int temp1,temp2,temp3;
temp1 = 199;
temp2 = BUFFERWIDTH;
temp3 = 199%BUFFERWIDTH;

CString txt;
txt.Format(_T("temp3 = %d"),temp3);
AfxMessageBox(txt);

按预期输出199.

#define WIDTH 100
#define BUFFERWIDTH 2*WIDTH
int temp1,temp2,temp3;
temp1 = 199;
temp2 = BUFFERWIDTH;
temp3 = 199%BUFFERWIDTH;

CString txt;
txt.Format(_T("temp3 = %d"),temp3);
AfxMessageBox(txt);

输出是100 ...

只是想知道是什么导致这个:)

Answer 1

阅读有关运算符优先级的信息,请注意您的说法199 % 2 * 100.

...

或者我应该说,(199 % 2) * 100......