Implement a program that, given a person’s name, prints a person’s initials

Question

can please someone help me finding the error in my code. their are no syntax error. but somewhere it is wrong since i am not getting my desired output. the functions gets() and toupper() are not getting implemented from the library.

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

    int toupper(char d);
    char gets(char a[100]);

    int main(void)
    {
        int i;
        char a[100];
        printf("enter your name \n");
        gets(a);
        printf("%c",toupper(a[0]));
        for(i=1;a[i]!='\0';i++)
        {
            if(a[i]==' ')
            {
                printf("%c",toupper(a[i+1]));
            }

        }
        printf("\n");
        return 0;
    }



    int toupper(char d)
    {
        return (d-32);
    }

    char gets(char a[100])
    {
        int i;
        for(i=0;a[i] != '\0'+1;i++)
         {
            scanf("%c",&a[i]);
         }
          return a[i];
    }

@user3125367 [DO NOT use `gets()`, it is dangerous](http://stackoverflow.com/q/1694036/2173917). use [`fgets()`](https://linux.die.net/man/3/fgets) instead. — Sourav Ghosh, Mar 07 '17 at 16:48
That mantra again. This code is too dangerous by itself, and gets() cannot add more. Please recall when you last used fgets() in production and realize that get-functions are there only for educational purposes, because all serious-business input is event-driven and v-buffered anyway. — user3125367, Mar 07 '17 at 16:57
@user3125367 - You want another mantra? How about not suggesting `gets` since it was removed in 2011 form the C standard, and new code should most definitely not be written with it. — StoryTeller - Unslander Monica, Mar 07 '17 at 16:59
@StoryTeller That's very good point, and that is not mantra, when you -std=c11. — user3125367, Mar 07 '17 at 17:01
@user3125367 - Glad you agree :) Good thing the standard committee listened to that mantra :P — StoryTeller - Unslander Monica, Mar 07 '17 at 17:02
Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example. — too honest for this site, Mar 07 '17 at 17:02
Ask yourself what the function `toupper` will do when passed an ... upper-case character, indeed any character that is *not* a lower-case letter. Names may have a hyphen or an apostrophe. — Weather Vane, Mar 07 '17 at 17:07
`for(i=0;a[i] != '\0'+1;i++)` is the same as `for(i=0;a[i] != 1;i++)`, so it loops until a character code of 1 is entered, likely Ctrl A — chux - Reinstate Monica, Mar 07 '17 at 17:12
Use `fgets()` to read a line of user input, then process the string. — chux - Reinstate Monica, Mar 07 '17 at 17:14

score 1 · Answer 1 · answered Mar 07 '17 at 17:42

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

int
main(int argc, char *argv[])
{
    char s[512];

    printf("Enter your name: ");
    fflush(stdout);

    if (fgets(s, sizeof(s), stdin)) {

        int scanning_for_first = 1;

        for (size_t i = 0; i < sizeof(s) && s[i] != '\n' && s[i] != '\0'; i++)
        {
            if (scanning_for_first) {
                if (!isalnum(s[i])) continue;
                printf("%c.", toupper(s[i]));
                scanning_for_first = 0;
            }

            if (!isalnum(s[i])) {
                scanning_for_first = 1;
            }
        }
    }
    printf("\n");

    return 0;
}

Enter your name: John Fitzgerald Kennedy
J.F.K.

Implement a program that, given a person’s name, prints a person’s initials

1 Answers1