Odd ouput

[me77]

Why doesn't this work? If you run it you'll see the odd output. at first it asks me like normal then i put in a then it says enter letter 2 enter letter 3 on the same line and it doest it to the end. then it skips the last for and doesnt print them.

#include <stdio.h>

int main(void)
{
        char alphabet[26],letters;
        int i;

        for(i=1; i<=26; i++)
        {
                printf("Enter letter %d of the alphabet: ", i);
                scanf("%c", &alphabet[letters]);
        }
        for(i=1; i<=26; i++)
                printf("%c", alphabet[letters]);

        return 0;
}

[brewbuck]

See the FAQ about scanf(), newlines, etc.

[vart]

letters - do you see anywhere in your code the variable to be initialized and modified?

and do not forget that scanf %c format leaves the \n character in the input stream

[me77]

letters - do you see anywhere in your code the variable to be initialized and modified?

and do not forget that scanf %c format leaves the \n character in the input stream

Ok i'll check it out on the FAQ. but yes i initialize the variable at char letters and its modified every time scanf inserts a letter into it. no?

[tabstop]

Ok i'll check it out on the FAQ. but yes i initialize the variable at char letters and its modified every time scanf inserts a letter into it. no?

char letters; does not initialize the variable.

And you never read in anything into letters -- but rather alphabet[letters].

[JDGATX]

Also, buffer overrun on your array alphabet. You have 26 elements, true, but you don't use element 0. Your for loop needs to go from 0 to 25, not 1 to 26. Array element 26 is out of bounds.

[me77]

char letters; does not initialize the variable.

And you never read in anything into letters -- but rather alphabet[letters].

so how would be the best way to put the letters into an array?

also i cant seem to find the thread about the scanf in the faq thread would be great if someone could please link me.

[JDGATX]

Remove the variable 'letters' entirely. Replace it with 'i' in your for loop.

scanf("%c", &alphabet[i]);

And also:

printf("%c", alphabet[i]);

[me77]

ok i did what you said but i still get this output

Enter letter 1 of the alphabet: a
Enter letter 2 of the alphabet: Enter letter 3 of the alphabet: b
Enter letter 4 of the alphabet: Enter letter 5 of the alphabet:

[brewbuck]

ok i did what you said but i still get this output

Enter letter 1 of the alphabet: a
Enter letter 2 of the alphabet: Enter letter 3 of the alphabet: b
Enter letter 4 of the alphabet: Enter letter 5 of the alphabet:

The '%c' conversion operator to scanf() does not skip whitespace. Therefore the second call to scanf() is consuming the newline which is still sitting in the input buffer, instead of reading the character which follows it. This is the issue discussed in the FAQ.

[me77]

oh i see now! thankyou.. i couldnt find the thread with that in it lol. anyways thanks for the simple explanation.
so how would you it?

[me77]

let me rephrase that... is it possible to do this program without removing scanf. i know that i could just do "%c%c%c.. 26 times but thats not convenient.

[NeonBlack]

Possible, but not the best way.

 
for(i=1; i<=26; i++)
{
     printf("Enter letter &#37;d of the alphabet: ", i);
     scanf("%c%c", &alphabet[letters], &enterkey);
}

Declare and use another char, "enterkey" (or whatever) that "eats up" the newlines.

[me77]

lol i cant believe i didnt think of that lol.. its late here.. anyways thanks that should work for now just to get an understanding of how everything works.. since im just doing this as an exercise.

[vart]

to eat up char just use %*c format:

scanf("%c%*c", &alphabet[letters]);