C program - confusing output

Question

I am trying to create a program that computes the value of a word by summing the values of its letters.

These are the letters and their corresponding value:

1 Point: A, E, I, L, N, O, R, S, T, U
2 Points: D, G
3 Points: B, C, M, P
4 Points: F, H, V, W, Y
5 Points: K
8 Points: J, X
10 Points: Q, Z

Here's the program:

#include <stdio.h>
#include <ctype.h>

int main(void)
{
    char ch; int sum=0;

    printf("Enter a word: ");

    while ((ch=getchar())!='\n') {
        toupper(ch);
        if (ch== 'A' || ch== 'E' || ch== 'I' || ch== 'L' || ch== 'N' || ch== 'O' || ch== 'R' || ch== 'S' || ch== 'T' || ch== 'U')
            sum+=1;

        else if (ch== 'D' || ch== 'G')
            sum+=2;

        else if (ch=='B' || ch== 'C' || ch== 'M' || ch== 'P')
            sum+=3;

        else if (ch=='F' || ch== 'H' || ch== 'V' || ch== 'W' || ch== 'Y')
            sum+=4;

        else if (ch=='K')
            sum+=5;

        else if (ch=='J' || ch== 'X')
            sum+=8;

        else if (ch=='Q' || ch== 'Z')
            sum+=10;
    }
    printf("\nScrabble value: %d",sum);

    return 0;
}

When I run the program it prints "Scrabble value: 0". Seems like the program is skipping the while loop entirely, maybe I am not using getchar properly, but I can't figure out what's wrong.

The points are the same points for each letter in the game scrabble.Is it so you are creating some program in connection with scrabble? — Spikatrix
– Spikatrix, Commented Jun 23, 2014 at 14:56
Yes, I am reading a book and creating this program was an exercise. — Sharod Saor
– Sharod Saor, Commented Jun 23, 2014 at 15:03
Then mark an answer as accepted by pressing the green tick mark beside the answer — Spikatrix
– Spikatrix, Commented Jun 23, 2014 at 15:08
Note that getchar() returns int, and might return EOF rather than an actual character. I/O is tricky. — unwind
– unwind, Commented Jun 23, 2014 at 15:19

perh · Accepted Answer · 2014-06-23 14:45:43Z

7

It should be ch = toupper(ch);

toupper does not modify it's argument.

And, while not in any way related to the issue, I would recommend using switch for code like this.

answered Jun 23, 2014 at 14:45

perh

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Comments

M__ · Accepted Answer · 2014-06-23 14:48:30Z

Your problem is in toupper(). The function does not alter your char directly, it returns the altered char.

#include <stdio.h>
#include <ctype.h>

int main(void)
{
    char ch; int sum = 0;

    printf("Enter a word: ");

    while ((ch = getchar()) != '\n') {
        ch = toupper(ch);
        if (ch == 'A' || ch == 'E' || ch == 'I' || ch == 'L' || ch == 'N' || ch == 'O' || ch == 'R' || ch == 'S' || ch == 'T' || ch == 'U')
            sum += 1;
        else if (ch == 'D' || ch == 'G')
            sum += 2;
        else if (ch == 'B' || ch == 'C' || ch == 'M' || ch == 'P')
            sum += 3;
        else if (ch == 'F' || ch == 'H' || ch == 'V' || ch == 'W' || ch == 'Y')
            sum += 4;
        else if (ch == 'K')
            sum += 5;
        else if (ch == 'J' || ch == 'X')
            sum += 8;
        else if (ch == 'Q' || ch == 'Z')
            sum += 10;
    }
    printf("\nScrabble value: %d", sum);
    return 0;
}

Nicolas Defranoux · Accepted Answer · 2014-06-23 14:46:19Z

0

toupper(ch); computes the uppercase of ch but does nothing with it. Your code works fine with UPPERCASE input. With lowercase input you just need to change

toupper(ch);

to

ch = toupper(ch);

answered Jun 23, 2014 at 14:46

Nicolas Defranoux

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Comments

s_bh · Accepted Answer · 2015-06-12 18:17:26Z

0

Unless you store the converted character to a variable it remains in the case in which it had been entered. 'toupper' is a function and to re-use the value it returns you must store a copy.

answered Jun 12, 2015 at 18:17

s_bh

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Comments

Alejandro Caro · Accepted Answer · 2016-07-03 23:12:06Z

0

Sentences may not be "loose" in a program, must be associated with others, in general with the assignment sign (=). Change ch = toupper(ch) by ch = toupper(ch)

edited Jul 3, 2016 at 23:12

answered Jul 3, 2016 at 22:53

Alejandro Caro

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