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5.7 Exercises

1. If x is 100 and z is 200, what is the output of the following:

   if (z = x)
             printf("z = %d, x = %d\n", z, x);

2. With the following declarations:

   int a = 10, b = 15, c = 25;
        float x = 15;
        double y = 30;
        long int m = 25L;

   What are the values and types of the following expressions:

   a + b / c * x;
        a + b / x * c;
        a + b / y * c;
        a + b / m * c;
   
        x + a / b;
        x + (int) a / b;

3. Evaluate the expressions following the declarations:

   int x, y, z;
        float u, v, w;
   
        x = 10; y= 20; z = 30;
   
        x = z / y + y;
        x = x / y / z;
        x = x % y % z

4. Evaluate the expressions:

   int x, y, z;
        float u, v, w;
        x = 10; y= 20; z = 30;
        u = 5.0; v = 10.0; w = 30.0;
   
        x = w / y + y;
        u = z / y + y;
        u = w / y + y;
        u = x / y / w + u / v;

5. What is the output of the following program?

   #define PRHAPS
   #define TWICEZ z + z
   
   main()
   {    int w, x, y, z;
        float a, b, c;
        w = 16; x = 5; y = 15; z = 8;
        a = 1.0; b = 2.0; c = 4.0;
   
        #ifdef PRHAPS
             x = 15;
             y = 5;
        #endif
   
        printf("(a). %d %d\n", x, y);
        printf("(b). %d\n", TWICEZ * 2);
        printf("(c). %f %f\n", w / z * a + c, z / w * b + c);
        printf("(d). %d\n", z % y % x);
   }

6. What will be the output in the following cases:

   1. #define SWAP(x, y)  int temp; temp = x; x = y; y = temp
      main()
      {    int x1 = 10, x2 = 20;
      
           SWAP(x1, x2);
           printf("x1 = %d, x2 = %d\n", x1, x2);
      }

   2. #define SWAP(x, y)  {int temp; temp = x; x = y; y = temp;}
      main()
      {    int x1 = 10, x2 = 20;
      
           SWAP(x1, x2);
           printf("x1 = %d, x2 = %d\n", x1, x2);
      }

   3. #define SWAP(x, y)  int temp; temp = x; x = y; y = temp
      main()
      {    int x1 = 10, x2 = 20;
      
           printf("Swapping Values\n");
           SWAP(x1, x2);
           printf("x1 = %d, x2 = %d\n", x1, x2);
      }

7. Write a while and a do...while loop to read and echo long integers until end of file. Allow for the possibility that the first input is an end of file.

8. Write a for loop to print out squares of integers in the sequence 5, 10, 15, 20, 25, etc. until 100.

9. Given the following declarations:

   int x = 100, y;

   What are the values of x and y after each of the following expressions is evaluated (the expressions are evaluated in sequence)?

   y = x++;
        y = ++x;
        y = --x;
        y = x--;

10. What are the values of the following expressions considered sequentially:

    x = 100; y = 200;
         y = y++ - ++x;
         y = ++y - x++;
         y = ++y * 2;
         y = 2 * x++;

11. Evaluate the following:

    x = 100; y = 200;
         y += 2 * x++;
         y -= 2 * --x;
         y += x;

12. Evaluate the following:

    x = 100; y = 200; z = 25;
         z = y > x ? x : y;
         z = (z >= x && z >= y) ? z - x * y : z + x * y;