15.06.2025

'C Programming, A Modern Approach' Chapter 2 Answers

I already have my answers in the various readmes on this repo here

You may have noticed there are no answers for Chapter 1. This is because Chapter 1 did not have an exercises/programming projects section.

Exercises

  1. Hello World

    back to basics with this one. The book asked whether I got a compiler warning but I actually didn't. Maybe they expect you to forget to include stdio.h.

  2. Parkinson's Law

    This one asks to identify the statements and directives in this program:

              
#include <stdio.h>
int main(void)
{
  printf("Parkinson's Law:\nWork expands so as to ");
  printf("fill the time\n);
  printf("available for its completion.\n");
  return 0;
}

    The directive is the "include" before the main function and the statements are all the printf functions and the final return.

    The output:

     
Parkinson's Law:

Work expands so as to fill the time

available for its completion.

  3. dweight.c Improvement

    • Height, length and width are all now initialised in a single line: 
      int height, width, depth, volume;
    • Removed weight instead calculating within printf: 
      printf("The weight of the box is %dkg.\n", (volume + 165) / 166);

  4. Uninitialised ints and floats

    The values were all zero for me. Maybe GCC initialises them as zero automatically.

  5. Illegal C identifiers

    • 100_bottles ❌ variables cannot begin with a number in C
    • _100_bottles ✅
    • one__hundred__bottles ✅
    • bottles_by_the_hundred_ ✅

  6. Adjacent Underscores

    It's a bad idea to have adjacent underscores (as in current__balance) because they could easily mistaken for a singular underscore.

Programming Projects

  1. tick.c

    This program prints asterisks in a tick shape as shown below:

    
       *
      *
     *
*   *
 * *
  *
    See Code

  2. sphereVolume.c

    This program calculates the volume of a sphere for a user-given radius

    See Code

  3. taxCalc.c

    This program calculates and displays an amount of money with tax added for a user-given amount

    See Code

  4. poly.c

    Calculates 3x^5 + 2x^4 - 5x^3 - x^2 + 7x - 6 for a user-given value of x

    See Code

  5. bills.c

    This program works out the smallest number of notes/coins (twenties, tens, fivers and pounds) needed to pay a bill provided by the user

    See Code

  6. interest.c

    This one works out the balance remaining on a loan for the next three months of payments taking into account interest provided by the user.

    See Code