1、判斷以下程序輸出結果
main()
{
char *p1=“name”;
char *p2;
p2=(char*)malloc(20);
memset (p2, 0, 20);
while(*p2++ = *p1++);
printf(“%s\n”,p2);
}
答案：Answer:empty string.
2、
main()
{
int x=20,y=35;
x=y++ + x++; 35+20=55
y= ++y + ++x; 36+(x=57)=94
printf(“%d%dn”,x,y);
}
Answer : 57 94
3、
main()
{
int x=5;
printf(“%d,%d,%dn”,x,x< <2,x>>2);
}
Answer: 5,20,1
3、
#define swap(a,b) a=a+b;b=a-b;a=a-b;
void main()
{
int x=5, y=10;
swap (x,y);
printf(“%d %dn”,x,y);
swap2(x,y);
printf(“%d %dn”,x,y);
}
int swap2(int a, int b)
{ int temp;
temp=a;
b=a;
a=temp;
return 0;
}
Answer: 10, 5
4、
main()
{
char *ptr = ” Cisco Systems”;
*ptr++; //++的優先級別高
printf(“%sn”,ptr);
ptr++;
printf(“%sn”,ptr);
}
Answer:isco Systems sco Systems
5、
main()
{
char s1[]=“Cisco”;
char s2[]= “systems”;
printf(“%s”,s1);
}
Answer: Cisco
6、
main()
{
char *p1;
char *p2;
p1=(char *)malloc(25);
p2=(char *)malloc(25);
strcpy(p1,”Cisco”);
strcpy(p2,“systems”);
strcat(p1,p2);
printf(“%s”,p1);
}
Answer: Ciscosystems
7、
main()
{
int x=10, y=15;
x = x++;
y = ++y;
printf(“%d %dn”,x,y);
}
Answer: 11, 16
8、
main()
{
int a=0;
if(a==0)
printf(“Cisco Systemsn”);
printf(“Cisco Systemsn”);
}
Answer: Two lines with “Cisco Systems” will be printed.