C Essentials – Part 2: SUMMARY TEST

C Essentials – Part 2: SUMMARY TEST

C Essentials – Part 2: SUMMARY TEST

  1. What is the value of the X variable at the following snippet?

    int X = 8;
X = X - X / 2;
X = X * X / 4;
X = X + 2 * X;
    • 16
    • 10
    • 12
    • 14

  2. What happens if you try to compile and run this program?

    #include <stdio.h>

struct S {
    int Var;
    struct S *Str;
};

int main(void) {
    struct S S[] = { { 8, NULL }, { 4, &S[0] }, { 2, &S[1] } };
    printf("%d", S[2].Str->Str->Var);
    return 0;
}
    • the program outputs 1
    • the program outputs 8
    • the program outputs 4
    • the program outputs 2

  3. What is the value of the X variable at the following snippet?

    float X = 2.0;
X = X + X * X;
X = X / X * X;
X = X / X + X;
    • 0.500000
    • 110.000000
    • 11.000000
    • 1.000000

  4. What happens if you try to compile and run this program?

    #include <stdio.h>

int main(void) {
    char *p = "\0\2\1\3\4";

         printf("%d", p[p[2] + *(p + 1) + p[0]);
    return 0;
}
    • the program outputs 2
    • the program outputs 4
    • the program outputs 8
    • the program outputs 1

  5. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <string.h>

int main(void) {
    char tt[20] = "0123456789";
    strcat(tt + 11, "123");

    printf("%d\n", strlen(tt) - tt[8] + '0');
    return 0;
}
    • the program outputs 1
    • the program outputs 2
    • the program outputs 8
    • the program outputs 4

  6. What happens if you try to compile and run this program?

    #include <stdio.h>

int fun(int *t) {
    return *(t + 3);
}

int main(void) {
    int arr[] = { 3, 2, 1, 0 };
    printf("%d\n", fun(arr - 2));
    return 0;
}
    • the program outputs 2
    • the program outputs 4
    • the program outputs 8
    • the program outputs 1

  7. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <string.h>

struct S {
    char S[8];
};

int main(void) {
    struct S S = { 'a', 'b', 'c', 'd' };
    printf("%d", sizeof(S.S) - strlen(S.S) + S.S[4]);
    return 0;
}
    • the program outputs 8
    • the program outputs 4
    • the program outputs 1
    • the program outputs 2

  8. What happens if you try to compile and run this program?

    #include <stdio.h>

int main(void) {
    int i = 3, j = i - 2 * i;
    switch(i j){
       case 1: j++;
       case 2: j--;
       case 3: j++; break;
       default: j = 0;
    }

    printf("%d", ++j);
    return 0;
}
    • the program outputs 4
    • the program outputs 0
    • the program outputs 2
    • the program outputs 1

  9. What happens if you try to compile and run this program?

    #include <stdio.h>

struct S {
    int Var;
    struct S *Str;
};

int main(void) {
    struct S S[] = { { 8, NULL }, { 4, &S[0] }, { 2, &S[1] } };
    printf("%d", S[2].Str->Str->Var);
    return 0;
}
    • the program outputs 3
    • the program enters an infinite loop and outputs nothing
    • the program outputs 1
    • the program outputs 2

  10. What is the value of the following integer literal?

    017
    • the literal is invalid
    • 15
    • 17
    • 23

  11. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    char t[] = { 'x', 'z', 'Y', 'Z', '2' , '0' };
    printf("%d\n", t[t[1] - t[0] - t[3] + t[2] + 3] - t[5]);
    return 0;
}
    • the program outputs 0
    • the program outputs 1
    • the program outputs 4
    • the program outputs 2

  12. What is the value of the Z variable at the end of the following snippet?

    int X = 1;
int Y = X + 2;\

y++;
int Z = Y;
--x;
y--;
Z = Z/ y * X * Y;
    • 3
    • 0
    • 1
    • 7

  13. Which of the following declarations is legal?

    • float floating;
    • float float;
    • float long;
    • float int;

  14. What happens if you try to compile and run this program?

    #include <stdio.h>
struct S {
    int S[3];
};

void f(struct S S) {
   S.S[0] = S.S[1] + S.S[2] - 4;
}

int main(void) {
    struct S S = { { 1, 4, 2 } };
    f(S);

    printf("%d",S.S[1] * S.S[0]);
    return 0;
}
    • the program outputs 8
    • the program outputs 1
    • the program outputs 4
    • the program outputs 2

  15. What happens if you try to compile and run this program?

    #include <stdio.h>
struct S {
    int S[3];
};

void f(struct S *S) {
   S->S[2] = 6 * S->S[0] + S->S[1];
}

int main(void) {
    struct S S = { { 1, 2 } }, *P = &S;
    f(P);

    printf("%d",S.S[2] / S.S[0]);
    return 0;
}
    • the program outputs 2
    • the program outputs 4
    • the program outputs 8
    • the program outputs 1

  16. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    float a = 3.14E0, *b = &a, **c = &b;
    **c = a + (a == *b);

    printf("%d", a);
    return 0;
}
    • the program outputs 2.140000
    • the program outputs 3.140000
    • the program outputs NULL
    • the program outputs 4.140000

  17. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <stlib.b>

int main(void) {
    float *t = 1 + (float *) malloc(sizeof(float) * sizeof(float));
    t--;
    *t = 8.0;
    t[1] = *t / 4.0;
    t++;
    t[-1] = *t / 2.0;

    printf("%f\n", *t);
    free(--t);
    return 0;
}
    • the program outputs 2.000000
    • the program outputs 8.000000
    • the program outputs 1.000000
    • the program outputs 4.000000

  18. What is the value of the X variable at the end of the following snippet?

    int X;
X = ('r' - 's') * ('A' / 'Z');
    • 1
    • 0
    • the snippet is invalid and will cause compilation error
    • 2

  19. What happens if you try to compile and run this program?

    #include <stdio.h>
#define ONE 1
#define TWO ONE + ONE

int main(void) {
    int i = 2;
    i = i - 2 * TWO;

    printf("%d\n", i);
    return 0;
}
    • the program outputs 1
    • the program outputs 2
    • the program outputs 4
    • the program outputs 0

  20. What happens if you try to compile and run this program?

    #include <stdio.h>

int main(void) {
    char t[4][4];

    printf("%d",sizeof(t) / sizeof(t[0]) / sizeof(t[0][0]));
    return 0;
}
    • the program outputs 8
    • the program outputs 2
    • the program outputs 1
    • the program outputs 4

  21. Which of the following string is the correct floating-point number(in the “C” language sense)?

    • 3E8
    • 3,0x10^8
    • 300,000,000
    • 3.0x10^8

  22. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i, s = 0, t[] = {16, 8, 4, 2, 1, 0};

    for(i = 5; t[i] > 2; i /= 2)
       s += t[i];

    printf("%d\n", s);
    return 0;
}
    • the program outputs 0
    • the program outputs 1
    • the program outputs 2
    • the program outputs 4

  23. Select the proper from for the following declaration:

    ptr is a pointer to pointer to pointer to double

    • the declaration is invalid and cannot be coded in C
    • doube ***ptr;
    • double **ptr;
    • double *ptr;

  24. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i, t[4];

    for(i = 0; i < 3; i++){
       t[i] = 4 - i;
       t[i + 1] = 2 * t[i];
    }

    printf("%d\n", t[2]);
    return 0;
}
    • the program outputs 1
    • the program outputs 2
    • the program outputs 0
    • the program outputs 4

  25. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    char s[20] = "?";
    FILE *f = fopen("fopen","w");
    int i = fputs("789",f);
    fclose(f);
    f = fopen("fopen","r");
    fgets(s + 1,3,f);  

    printf("%c\n", s[2] - s[3]);
    fclose(f);
    return 0;
}
    • the program outputs 8
    • the program outputs 1
    • the program outputs 4
    • the program outputs 2

  26. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct S {
    char *S;
};

int main(void) {
    struct S *S = (struct S *) malloc(sizeof(struct S));
    S -> S = "123\0""45678";

    printf("%d",strlen(S -> S + 5) + S -> S[3]);
    free(S);
    return 0;
}
    • the program outputs 1
    • the program outputs 2
    • the program outputs 4
    • the program outputs 8

  27. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i = 5, j =16;
    while(j >= 0) {
        i /= 2;
        j -= i / 2;
    }

    printf("%d", i + j);
    return 0;
}
    • the program outputs 2
    • the program outputs 1
    • the program enters an infinite loop and outputs nothing
    • the program outputs 3

  28. What happens if you try to compile and run this program?

    #include <stdio.h>

int main(void) {
    int i = -1, j = 1;
    
    for(i++; i++; i++)
       j++;

    printf("%d", i + j);
    return 0;
}
    • the program outputs 2
    • the program outputs 1
    • the program outputs enters an infinite loop and outputs nothing
    • the program outputs 3

  29. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i = 1, j = 0, k;
    k = (i >> j) + (j >> i) + (i >> i) + (j >> j);
    k <<= i;

    printf("%d", k);
    return 0;
}
    • the program outputs 0
    • the program outputs 2
    • the program outputs 1
    • the program outputs 4

  30. What is the meaning of the following declaration?

    float *f(int);
    • f is function (int) returning pointer to float;
    • f is a pionter to function (int) returning float;
    • the declaration is erronous
    • f is a pointer to function (float) returning int;

  31. What is the value of the following integer literal?

    0x17

    • 23
    • the literal is invalid
    • 17
    • 15

  32. Which of the following string is  a legal variable name?

    • 2antiworld
    • anti_world
    • anti world
    • anti:world

  33. What happens if you try to compile and run this program?

    #include <stdio.h>
float f(float v) {
       v = v / 2.0;
   return v + v;
}

int main(void) {
    float x = 4;
    f(x);

    printf("%f", x);
    return 0;
}
    • the program outputs 4.000000
    • the program outputs 2.000000
    • the program outputs 8.000000
    • the program outputs 1.000000

  34. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <string.h>

char *f(int p, char *s) {
   s[p + 2] = '\0';
   return s - 1;
}

int main(void) {
    char s[] = "ABCDEF";
    int i = strlen(f(1, s + 2));

    printf("%d\n", i);
    return 0;
}
    • the program outputs 1
    • the program outputs 4
    • the program outputs 8
    • the program outputs 2

  35. What happens if you try to compile and run this program?

    #include <stdio.h>
#include <string.h>

int main(void) {
   char tt[20] = "9081726354";
   strcpy(tt, tt + 3);

    printf("%d\n", strlen(tt) - tt[9] + '5');
    return 0;
}
    • the program outputs 2
    • the program outputs 4
    • the program outputs 1
    • the program outputs 8

  36. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i = 1, j;

    for(j = 0; j ; j--)
       i *= 2;

    printf("%d",i + j);
    return 0;
}
    • the program enters an infinite loop and outputs nothing
    • the program outputs 1
    • the program outputs 3
    • the program outputs 2

  37. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
    int i = 1;

    if(i = 0)
         i = 2;
    else
         i = 3;

         printf("%d\n",i);
    return 0;
}
    • the program outputs 1
    • the program outputs 3
    • the program outputs 4
    • the program outputs 2

  38. What happens if you try to compile and run this program?

    #include <stdio.h>
char *f(char *p) {
    return p += 2;
}

char *g(char *p) {
    return --p;
}

int main(void) {
    char *s = "ABCDEFGHIJ";
    char p = *f(g(f(s + 1)));
    printf("%d",p - 'A');
    return 0;
}
    • the program outputs 8
    • the program outputs 4
    • the program outputs 1
    • the program outputs 2

  39. What happens if you try to compile and run this program?

    #include <stdio.h>
int main(void) {
   int i = 5, j = i - 4 * i;
   swicth(j) {
        default: j = 2;
        case 1: j--;
        case 2: j++;
        case 0: j--; break;

    }

    printf("%d", j++);
    return 0;
}
    • the program outputs 2
    • the program outputs 0
    • the program outputs 4
    • the program outputs 1

  40. What happens if you try to compile and run this program?

    #include <stdio.h>

int main(void) {
    int x = 1, y = 1;
    float k = -1e0, m = 2el;

    printf("%d\n", (x >= y) + (x >= y) + (k >= y) + (m >= k) + ('q' <= 'z'));
    return 0;
}
    • the program outputs 2
    • the program outputs 4
    • the program outputs 1
    • the program outputs 2