Creating columns in C language

Question

I have these lines in my program:

printf("%-29s\n",("%s, Capital", CO));
printf("%-29s\n",("%s, Drawing",CO));

and when I run the program, it only shows the %s equivalent (CO) instead of "%s, Drawing"

Please help?

Answer 1

You used the comma operator and the behavior is normal.

An expression with comma operator A, B means that first evaluate A, ignore its result, then evaluate B and the result of comma operator will be its value.

If you want to show "%s, Drawing", print it.

printf("%-29s\n","%s, Drawing");

Answer 2

As MikeCAT has already stated, you have used the comma operator. If you want to left-align the compound string, you can achieve it by first printing to a temporary buffer with snprintf:

    char tmp[30];

    snprintf(tmp, sizeof(tmp), "%s, Capital", CO);
    printf("|%-29s|", tmp);

    snprintf(tmp, sizeof(tmp), "%s, Drawing", CO);
    printf("|%-29s|", tmp);

Of course, given that you print a newline directly after the string (and the justification is therefore somewhat pointless), you might as well just print the desired format directly:

    printf("%s, Capital\n", CO);
    printf("%s, Drawing\n",CO);