char yes_no = 'z';
int i = 0;
while ((yes_no != 'y') && (yes_no != 'n') )
{
read(0, &yes_no, 1);
printf("%dA file already exists at your write location. Over write? (y/n)\n", i++);
}
輸出看起來是這樣的:爲什麼這會在每次迭代中打印消息兩次?
0A file already exists at your write location. Overwrite? (y/n)
1A file already exists at your write location. Overwrite? (y/n)
a
2A file already exists at your write location. Overwrite? (y/n)
3A file already exists at your write location. Overwrite? (y/n)
...等。
爲什麼它會經過循環兩次而不是每次都等待用戶輸入?
爲什麼不通過調試器運行它並找出? –