单项选择题
#define sub1(a,b) {char c;c=a;a=b;b=c;}
#define sub2(a,b) {char c;c=*a;*a=b;b=c;}
#define sub3(a,b) {char c;c=*a;*a=*b;*b=c;}
则以下程序段的输出结果是( )。
char a,b;
a='A';b='B';sub3(&a,&b);putchar(a); putchar(b);
a='A';b='B';sub2(&a,b);putchar(a); putchar(b);
a='A';b='B';sub1(a,b);putchar(a);putchar(b);
A、BABBAB
B、ABBBBA
C、BABABA
D、以上都不对
#define sub1(a,b) {char c;c=a;a=b;b=c;}
#define sub2(a,b) {char c;c=*a;*a=b;b=c;}
#define sub3(a,b) {char c;c=*a;*a=*b;*b=c;}
则以下程序段的输出结果是( )。
char a,b;
a='A';b='B';sub3(&a,&b);putchar(a); putchar(b);
a='A';b='B';sub2(&a,b);putchar(a); putchar(b);
a='A';b='B';sub1(a,b);putchar(a);putchar(b);
A、BABBAB
B、ABBBBA
C、BABABA
D、以上都不对