单项选择题
要求通过while循环不断地将读入的字符输出,当读入字母W时结束循环。若变量已正确定义,下面正确的程序段是
A、while ( (ch=getchar() ) != 'N' ) printf(" %c ", ch);
B、while ( ch=getchar() != 'N' ) printf(" %c ", ch);
C、while ( (ch=getchar() ) == 'N' ) printf(" %c ", ch);
D、while ( ch=getchar() == 'N' ) printf(" %c ", ch);