Q: Arrays and Functions Homework - c

Question

To put it bluntly, as it stands, I am not very good at coding at this current time. I am really trying to get these functions completed, I am just having trouble with the execution on some of them.
Basically, there are 10 functions ( 6 of which I have finished? ) that need to be created.
There is an int main() but, besides a string that needs to be fixed, the int main() does not need to be touched.
I will post the program (mostly so you can see my work) in addition to the int main() so that if someone wants to check the intent, they can see it. Even though I have posted the whole program, the only ones that I really want to focus on are the makeUpper, and the functions that have nothing in them because I really don't understand how to copy and edit a string into another array.
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
void makeUpper( char orig[], char result[] )
{
/*
int i = 0;
while ( str[i] != '\0' )
{
if ( str[i] >= 'a' && str[i] <= 'z' )
str[i] = str[i] - 32;
k++;
}
*/
}
int countDigit( char str[] )
{
int i;
int count = 0;
int len;
len = strlen(str);
for ( i = 0; i < len; i++ )
{
if ( i >= '0' && i <= '9' )
count++;
}
return count;
}
int onlyLetters( char orig[], char letters[] )
{
}
int countOdd( int A[], int N )
{
int i;
int odd = 0;
for ( i = 0; i < N; i++ );
{
if ( A[i] % 2 != 0 )
odd++;
}
return odd;
}
int sumList( int A[], int N )
{
int i;
int sum = 0;
for ( i = 0; i < N; i++ );
sum = sum + A[i];
return sum;
}
void addToEach( int A[], int N, int val )
{
int i;
for ( i = 0; i < N; i++ )
A[i] + val;
printf("%d", A[i]);
}
void copyNumList( int orig[], int N, int result[] )
{
}
// populate list A with N items, random in range L to H
void fillNumList( int A[], int N, int L, int H )
{
}
// print the list, 10 items per line
void printList( int A[], int N )
{
int i;
for ( i = 0; i < N; i++ )
printf("%d ", A[i]);
printf("\n");
}
void rept( int n, char c )
{
int i;
for ( i = 0; i < n; i++ )
printf("%c", c);
printf("\n");
}
int main()
{
char line[100], other[100];
int i, len;
printf("Phrase: ");
fgets( line, 100, stdin );
// fix the string....
// ...
// really, do this
// ...
rept(10,'-');
printf("Orig: ##%s##\n", line);
rept(10,'-');
makeUpper( line, other );
printf("toupper: %s\n", other);
rept(10,'-');
i = countDigit( line );
printf("%d digits\n", i);
rept(10,'-');
len = onlyLetters( line, other );
printf("only letters: %s\n", other );
printf(" new len %d\n", len);
int nums[30], vals[30];
int many = 19;
rept(5, '-');
fillNumList( nums, many, 3, 11 );
printList( nums, many );
rept(5, '-');
i = countOdd( nums, many );
printf("%d odd values\n", i);
rept(5, '-');
i = sumList( nums, many );
printf("%d is sum\n", i);
rept(5, '-');
copyNumList( nums, many, vals );
printf("Copy\n");
printList( vals, many );
rept(5, '-');
addToEach( vals, many, 4 );
printf("Add 4\n");
printList( vals, many );
rept(5, '-');
printf("Orig\n");
printList( nums, many );
rept(5, '-');
return 0;
}

Answer 1

To answer the one almost-well-defined question (regarding makeUpper):
First, str is not a variable. You have orig and result, and haven't declared str anywhere.
Now, if str were orig, you'd be correctly uppercasing the characters in the original string. However, the task is to leave the original string alone and make an uppercased copy. The former is called "destructive operation" (as the original contents are not preserved); the latter, a "non-destructive operation" (for obvious reasons). Here are the changes needed to make your function non-destructive:
void makeUpper( char orig[], char result[] )
{
int k = 0;
do
{
if ( orig[k] >= 'a' && orig[k] <= 'z' )
result[k] = orig[k] - 32;
else
result[k] = orig[k];
} while ( orig[k++] != '\0' );
}
Notice that I iterate and test on orig, but assign to result.
onlyLetters should be similar; but you will need two index variables, not just k, since you will want to progress through orig and result at different pace (you'll only want to copy a character when it's a letter, and you'll only want to progress through result when you do a copy - as opposed to orig, which you'll always consume one character per loop).
As you have not stated what your misunderstanding is about copyNumList and fillNumList, I cannot give you any help there.
EDIT: I forgot about the terminator (and didn't test it); thanks Tom Karzes! Because the zero also needs to be copied, your loop is changed from while (condition) { ... } to do { ... } while (condition) - instead of testing whether we're at end and then doing things if we're not, we'll do the thing first, and only afterwards ask if we're done. This also requires the increment to be done after the test, so k++ got moved. If this is too weird for you, you can get the same effect like this, by explicitly adding the terminator after the loop is done:
void makeUpper( char orig[], char result[] )
{
int k = 0;
while ( orig[k] != '\0' )
{
if ( orig[k] >= 'a' && orig[k] <= 'z' )
result[k] = orig[k] - 32;
else
result[k] = orig[k];
k++;
}
result[k] = '\0';
}