4.下列程序的输出结果是( )
#include <stdio.h>
void main()
{ int a = 55, b = 50, c = 60, d; d = a > 20 ? b : c;
switch(d)
{ case 40:printf(“%d,”, a);
case 50 : printf(“%d,”, b);
case 60 : printf(“%d,”, c);
default : printf(“$\n”);
}
}
a.50,60
b.50,$
c.60,$
d.50,60,$