CSPP 50101 - Lab 2

Exercise 0:

This program ex1.c goes into an infinite loop because it has a run-time error, meaning that it compiles but does not run as intended. Here is what this program should output:

Enter a number, 1-10: 6
123456 

Fix this program so that it displays the correct output, as shown above.

HINT: In C, whitespace and indention are not used to determine the start or end a block of code. If the body of a loop or if statement has more than one statement then you must enclose it in curly braces. For example:

  if(n>=10)
  {
    printf("Invalid entry\n");
    return 0;
  }

$ ./ex1
Enter a number, 1-10: 7
7654321

Exercise 2: ex2.c

$ ./ex2
Enter a word: Mississippi
Mississippi starts with: M
$ ./ex2
Enter a word: M
M starts with: M
M only has one letter!

  if (str[1]=='\0')
    printf("%s only has one letter!\n",str);

Your task for this exercise is to modify ex2.c so that it also displays the length of the string.

$ ./ex2
Enter a word: Mississippi
Mississippi starts with: M
Mississippi has 11 letter(s).
$ ./ex2
Enter a word: M
M starts with: M
M has 1 letter(s).

Also note that in this example, the ampersand (&) is not used with scanf() when a string is read from standard input:

  printf("Enter a word: ");
  scanf("%s",str);

Exercise 3: ex3.c

File ex3.c already has a main() function that calls num_quarters():

int main()
{
  int m;

  printf("How many minutes will your car be parked?: ");
  scanf("%d",&m);

  printf("Number of quarters needed: %d\n",num_quarters(m));

  return 0;
}

$ ./ex3
How many minutes will you be parked?: 4
Number of quarters needed: 1
$ ./ex3
How many minutes will you be parked?: 5
Number of quarters needed: 1
$ ./ex3
How many minutes will you be parked?: 6
Number of quarters needed: 2

char starts_with(char str[])
{
  return str[0];
}

  printf("%s starts with: %c\n",str,starts_with(str));

For this exercise, add another function to ex4.c called string_length(). This function should return the length of the string, in characters. (You can refer back to your code in Exercise 2.)

Also add a printf() statement to main() to test your new function. Your output should look like this:

Enter a word: Mississippi
Mississippi starts with: M
Mississippi has 11 letter(s).

Part 4 - Submitting your assignment

First, be sure that every source file you submit includes this information in comments at the top of the file:

• Your first and last name
• Your username
• Any other comments you want to add about your program (optional)

  /* Sonjia Waxmonsky
   * wax
   * 
   * ex2.c: Converts from USD to JPY
   * 
   * Uses exchange rates from June 22, 2011
   *
   */

Also include a simple README file in your lab2 directory. This file should include your first and last name, your username, the list of files that you are submitting, and any other comments or questions for the Lab TA. For example:

Sonjia Waxmonsky
wax

ex1.c
ex2.c
ex3.c
ex4.c 

Do not submit any compiled binary files

You will submit this lab with the hwsubmit program.

$ hwsubmit cspp50101lab <path to your lab2 directory>