049[1].c面试时的读程序题.txt

总结了一些软硬件方面的笔试面试题

C面试时的读程序题ZZ 
shury 发表于 2004-12-5 17:50:00 

What will print out? 
main() 
{ 
        char *p1=“name”; 
        char *p2; 
        p2=(char*)malloc(20); 
        memset (p2, 0, 20); 
        while(*p2++ = *p1++); 
        printf(“%sn”,p2); 

} 

Answer:empty string. 

What will be printed as the result of the operation below:

main() 
{ 
    int x=20,y=35; 
    x=y++ + x++; 
    y= ++y + ++x; 
    printf(“%d%dn”,x,y); 
} 

Answer : 5794 

What will be printed as the result of the operation below:

main() 
{ 
    int x=5; 
    printf(“%d,%d,%dn”,x,x< <2,x>>2); 
}

Answer: 5,20,1 

What will be printed as the result of the operation below:

#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
10, 5 

What will be printed as the result of the operation below:

main()
{ 
    char *ptr = ” Cisco Systems”; 
    *ptr++; printf(“%sn”,ptr); 
    ptr++; 
    printf(“%sn”,ptr); 
} 

Answer:Cisco Systems
isco systems 

What will be printed as the result of the operation below:

main()
{ 
    char s1[]=“Cisco”; 
    char s2[]= “systems”; 
    printf(“%s”,s1); 
} 
Answer: Cisco 

What will be printed as the result of the operation below:

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 

The following variable is available in file1.c, who can access it?:

static int average;

Answer: all the functions in the file1.c can access the variable. 

WHat will be the result of the following code?

#define TRUE 0 // some code 
while(TRUE) 
{ 

    // some code 

} 

Answer: This will not go into the loop as TRUE is defined as 0. 

What will be printed as the result of the operation below:

int x; 
int modifyvalue() 
{ 
    return(x+=10); 
} 
int changevalue(int x) 
{ 
    return(x+=1); 
} 

void main()
{ 
    int x=10; 
    x++; 
    changevalue(x); 
    x++; 
    modifyvalue(); 
    printf("First output:%dn",x); 

    x++; 
    changevalue(x); 
    printf("Second output:%dn",x); 
    modifyvalue(); 
    printf("Third output:%dn",x); 

} 

Answer: 12 , 13 , 13 

What will be printed as the result of the operation below:

main()
{ 
    int x=10, y=15; 
    x = x++; 
    y = ++y; 
    printf(“%d %dn”,x,y); 
} 

Answer: 11, 16 

What will be printed as the result of the operation below:

main()
{ 
    int a=0; 
    if(a==0) 
        printf(“Cisco Systemsn”); 
        printf(“Cisco Systemsn”); 
} 

Answer: Two lines with “Cisco Systems” will be printed.