Thread: Problem with loop stopping at wrong time

Hello again.
I have created the following program to count the number of times each letter of the alphabet appears in a textfile. It works properly, unless there are no occerences of a certain character. Instead of just returning the value 0, it stops and any other letter in the alphabet after it that is in the file dosnt get counted\printed and I can't figure out why. Any ideas??

Code:

#include <stdio.h>
#include <stdlib.h>

char inputArray[1024], inFile[128];
FILE *in;
int charCount, countArray[26] = {0}, aRep, *ptr;
float lettotal, percentage;

void main()
{

	printf("\nInput name of plaintext file, including full path:\n");
	gets(inFile);

	if ((in = fopen(inFile, "r")) == NULL)
	{
		printf("\nCould not open file to be converted\n");
		exit(8);
	}

	while (aRep != EOF)
	{
		aRep = fgetc(in);
		
		if (aRep >= 97 && aRep <= 122)
			{
			aRep = aRep - 32;
			}
		
		if (aRep >= 65 && aRep <= 90)
		{
		inputArray[charCount] = aRep;
		charCount++;
		}
	}

	inputArray[charCount] = '\0';
	charCount = 0;
	
	for (charCount = 0; charCount != '\0'; charCount++)
	{
		aRep = inputArray[charCount] - 65;
		countArray[aRep] = countArray[aRep] + 1;
	}
	
	countArray[charCount] = '\0';
	charCount = 0;
	printf("Number of each letter in file:\n");

	for (charCount = 0; countArray[charCount] != '\0';  charCount++)
	{
		aRep = charCount + 65;
		printf("%c:%d\t", aRep, countArray[charCount]);
	}
}

Thanks
-Chris

P.S. I know there are a couple of unused variables and a pointer, they are for somthing else it needs to do later once this part works =)

It stops because you tell it to stop. They're all counted. However, you should be doing something like:

Code:

for( charCount = 0; charcount < lettersinthealphabet; charCount++ )
{
    if( countArray[ charCount ] )
    {
        ...do fun stuff...
    }
}

Also, if you mean 'A', say 'A'. Don't force some arbitrary integer value in all of your comparisons. The language cares little about implementation specific character sets. If you want to check from 'A' to 'Z' and subtract 'A' from it, then do so.


Quzah.

You might tinker with this and add perhaps an isalpha from <ctype.h>.

[the usual]
Don't use void main().
Don't use gets.
Check for EOF after each input.
FAQ.
[/the usual]

Or you can just use

Code:

aRep = toupper(aRep);

since toupper() doesn't do anything to non-lowercase letters.

The isalpha bit I mentioned was for counting letters only, by the way.

Code:

      static const char alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
      int     ch, count [ sizeof alphabet / sizeof *alphabet - 1 ] = {0};
      size_t  i;
      while ( (ch = fgetc(file)) != EOF )
      {
         if ( isalpha(ch) )
         {
            const char *found = strchr(alphabet, toupper(ch));
            if ( found != NULL )
            {
               ++count [ found - alphabet ];
            }
         }
      }

Actually, A to Z is guarinteed to be consecutive.

Code:

5.2.1 Character sets
1 Two sets of characters and their associated collating sequences shall be defined: the set in
which source files are written (the source character set), and the set interpreted in the
execution environment (the execution character set). Each set is further divided into a
basic character set, whose contents are given by this subclause, and a set of zero or more
locale-specific members (which are not members of the basic character set) called
extended characters. The combined set is also called the extended character set. The
values of the members of the execution character set are implementation-defined.
2 In a character constant or string literal, members of the execution character set shall be
represented by corresponding members of the source character set or by escape
sequences consisting of the backslash \ followed by one or more characters. A byte with
all bits set to 0, called the null character, shall exist in the basic execution character set; it
is used to terminate a character string.
3 Both the basic source and basic execution character sets shall have the following
members: the 26 uppercase letters of the Latin alphabet

A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
the 26 lowercase letters of the Latin alphabet

a b c d e f g h i j k l m
n o p q r s t u v w x y z
the 10 decimal digits

0 1 2 3 4 5 6 7 8 9
the following 29 graphic characters

! " # % & ' ( ) * + , - . / :
; < = > ? [ \ ] ^ _ { | } ~
the space character, and control characters representing horizontal tab, vertical tab, and
form feed. The representation of each member of the source and execution basic
character sets shall fit in a byte. In both the source and execution basic character sets, the
value of each character after 0 in the above list of decimal digits shall be one greater than
the value of the previous.

Read the last line.


Quzah.

In both the source and execution basic character sets, the value of each character after 0 in the above list of decimal digits shall be one greater than the value of the previous.

That's just the digits 0-9.

[edit]Thus allowing EBCDIC in C.

Yup, that's just for 0-9. Look up EBCDIC.

Edit: Dave's edit makes my post redundant

Ah, I read it as:

"Each character's value, after zero (since that's set aside from NULL), will be 1 less then the one after it."

Thus, if 'C' is given 23, 'D' will be 24. I was thinking it pertained to every list above, and when it said "zero", it meant "the character whose value is zero", not the digit zero.

[edit]
My eyes apparently glazed over when they hit the phrase "decimal digits" in the last sentence. :P Although, come to think of it, I'm not sure what I was thinking, since I've heard of EBDIC, and knew it was a different setup. Just not thinking clearly today. Must need more beer.
[/edit]

Quzah.

In both the source and execution basic character sets, the value of each character after 0 in the above list of decimal digits shall be one greater than the value of the previous.

It specifically mentions "the above list of decimal digits" as the criterion for the "one greater than the value of the previous". The only list of decimal digits above are 0,1,2,3,4,5,6,7,8,9.

Edit: and if it pertained to all the sets above, it would render ASCII non-conformant, since the graphic characters are not all contiguous