Thread: Printing Extra Characters such as Sigma and Smile Face. HELP

Just a few other things to take note of:

• void main() should be int main(), and you should return 0 unless you are compiling with respect to the 1999 edition of the C standard
• gets() should be avoided because it makes your program vulnerable to buffer overflow. Use fgets() instead, or scanf() with an appropriate field width for the format specifier.
• The non-standard functions clrscr() and getch() are probably unnecessary here, but if you do want to use them, you should #include <conio.h>
• You should indent your code more consistently.

Originally Posted by tabstop

Strings must end in a \0 character, unless you want the random bits of stuff after them to also print out.

how can i assign the last value to be \0 ?

Originally Posted by laserlight

Just a few other things to take note of:

• void main() should be int main(), and you should return 0 unless you are compiling with respect to the 1999 edition of the C standard
• gets() should be avoided because it makes your program vulnerable to buffer overflow. Use fgets() instead, or scanf() with an appropriate field width for the format specifier.
• The non-standard functions clrscr() and getch() are probably unnecessary here, but if you do want to use them, you should #include <conio.h>
• You should indent your code more consistently.

i'm using the old Turbo C program. How to use fgets()?
i tried using scanf() but after the first word i enter, it wont be printed already.

Originally Posted by tanpearl

How to use fgets()?

It can be as simple as:

Code:

fgets(s, 80, stdin);

Unfortunately, the newline from entering input is almost always placed into the string, so you should remove it, usually with strchr(). However, since you are going to loop over the characters of the string...

Originally Posted by tanpearl

how can i assign the last value to be \0 ?

Instead of using periods ('.') to mark the characters that are unused, I would simply use null characters and thus initialise s to an empty string:

Code:

char s[80] = "";

This means that you can ditch the first loop since it is no longer necessary. Next, after you have read in the string, you should loop with a condition of a < 79, not 80, since you want to leave at least one null character to mark the end of the string. In the loop body, you no longer need to check for spaces and periods, but instead you can check for '\n' and replace it with a '\0', thus getting rid of the unwanted newline (if it is present).

EDIT:
tabstop does have a point though: since you intend to ignore unused characters, you should be looping with a condition of a <79 && s[a] != '\0' so that you stop once you reach a null character.

That is because you insert null characters where you should insert spaces. The way to handle the null character is to copy it to b, and then terminate the loop.

There really should be an Adventures of Sigma and Smiley-Face.

What's funny is when I ran the Original Post, it worked fine in the sense that there was no garbage in it and it does what it looks like. I changed the last line to this:

Code:

printf("\n+%s+\n",b);

Output:

Code:

Type a string less than 80 characters: a string less than...80 characters
The string types is:a string less than...80 characters

+- ------ ---- ----   -- -----------                                             a string less than...80 characters+

This might be harder to get without a widescreen monitor

No, do something like this:

Code:

int a;
char s[80], b[80] = "";

/* read into s */

for (a = 0; a < 79 && s[a] != '\0'; a++)
{
    if (s[a] == ' ')
    {
        b[a] = ' ';
    }
    else
    {
        b[a] = '-';
    }
}

Notice that the loop condition now accounts for the null character. I chose to initialise b to an empty string instead of copying the null character from s to b. Most of all, notice that I used s[a] in the comparison instead of b[a].

Note that if you are not going to do anything with s, then you might as well do without b and just use s. By the way, try to use more descriptive names than s and b. It is fine to use a for a loop index, but it can be a little confusing when you also have a char array named b (it can be expected that a and b "go together").

EDIT:
Oh wait, I notice that you used strcpy(), in which case it is correct to compare with b[a] instead of s[a]. However, it also makes either s or b redundant.