Array struct toupper for whole string and after space

Question

I'm trying to put in upper case a first letter in a name. Something does not work. Also, I want to put whole surname in upper case. Which doesn't work too. Somehow only the first letter(of the above mentioned) get an upper case.

I have this code, and it does not work as expected:

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

struct Student
{
    char name[50];
    char surname[50];
    int year_of_birth;
};

void display(struct Student array[],int size);

int main()
{
    int n;
    printf("enter number: ");
    scanf("%d",&n);

    struct Student* array = malloc(n*sizeof(array));


    for(int i=0; i<n; i++)
    {
        printf("enter name: ");
        scanf(" %[^\n]*c",array[i].name);
        printf("enter surname: ");
        scanf(" %[^\n]*c",array[i].surname);
        printf("enter birth year: ");
        scanf(" %d",&array[i].year_of_birth);
    }

    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            array[i].surname[j] = toupper(array[i].surname[j]);
            array[i].name[0] = toupper(array[i].name[0]);
            if(isspace(array[i].name[j]))
                array[i].name[j+1] = toupper(array[i].name[j+1]);

        }
    }


    puts("");
    puts("::SHOWING::");

    display(array,n);


    return 0;
}

void display(struct Student array[],int size)
{
    for(int i=0; i<size; i++)
    {
        printf("Student info %d: %s %s %d \n",i+1,array[i].name,array[i].surname,array[i].year_of_birth);
    }

}

The output:

enter number: 2

enter name: olivia emma

enter surname: james

enter birth year: 2000

enter name: john noah

enter surname: Smith

enter birth year: 2002

::SHOWING:: Student info 1: Olivia emma JAmes 2000 Student info 2: John noah SMith 2002

Expected output:

Student info 1: Olivia Emma JAMES 2000 Student info 2: John Noah SMITH 2002

Please show your input, the actual output, and the expected output. — n. m. could be an AI, Jun 04 '22 at 09:43
Your `malloc` call is wrong. You should not allocate for `n` times the size of a `Student *`, what you are doing now. It should be either `n * sizeof(struct Student)` or `n * sizeof *array`. — Cheatah, Jun 04 '22 at 09:46
Explain what the inner loop with `j` is for. It makes no sense. Maybe you should consider the fact that you don't have a call to `strlen` anywhere. — Cheatah, Jun 04 '22 at 09:49
Also don't use hacks like `scanf(" %[^\n]*c", ...)`. Use `fgets`, check the return value, error out if the input string is too long. The scanf hack will just happily proceed to overwrite your memory. — n. m. could be an AI, Jun 04 '22 at 09:52
Okay thanks guys, I fixed the malloc, and implemented the strlen for the second loop and now its working. — manjitolo, Jun 04 '22 at 09:57

Vlad from Moscow · Answer 1 · 2022-06-04T10:15:12.030

For starters you are allocating a memory of an invalid size

struct Student* array = malloc(n*sizeof(array));

It seems you mean

struct Student* array = malloc(n*sizeof(*array));

In these calls of scanf

    scanf(" %[^\n]*c",array[i].name);
    printf("enter surname: ");
    scanf(" %[^\n]*c",array[i].surname);

the conversion specifiers *c are redundant. White space characters will be skipped in any case due to leading spaces in the format strings. So you could write

    scanf(" %49[^\n]",array[i].name);
    printf("enter surname: ");
    scanf(" %49[^\n]",array[i].surname);

For the data member surname you could use a loop as for example

   for ( char *p = array[i].surname; *p != '\0'; ++p )
   { 
        *p = toupper( ( unsigned char )*p );
   }

For the data member name you could use another loop

  #include <string.h>

  //...

  for ( char *p = array[i].name; *p != '\0'; p += strspn( p, " \t" ) )
  {
      *p = toupper( ( unsigned char )*p );
      p += strcspn( p, " \t" );
  }

Array struct toupper for whole string and after space

1 Answers1