Thread: Using structures 1st time..I am stuck

This program I am trying to write has a structure of persons with a first name last name and age for each.

What I need it to do it display the order of the persons before sorting and then display the persons after sorting by age.

So far I have written the overall program but am stuck at the most important step...which is defining the functions that will be doing all of the work.

For sort_by_age I want use bubble sorting by writing the function myself and for print_person_info I am confused on how to print data out of the struct. I am pretty lost here please help me out thank you.

Code:

#include <stdio.h>
struct person
{
   char first_name[20];
   char last_name[20];
   int age;
};
void print_person_info(struct person clone);
void sort_by_age(int n, struct person a[]);

int main(void)
{
   int I, n=5;
  struct person student[5] =
  {
   { "Bob",   "Smith",    21},
   { "Jimmy", "John",     18},
   { "Amy",   "Goldberg", 20},
   { "Dan",   "Marlo",    17},
   { "Sally", "Sorrow",   16}
  };
   for(I=0; I<n; I++)
    print_person_info(student[I]);
    sort_by_age(n, student);
  
printf("------AFTER SORTING-------\n");
 for(I=0; I<n; I++)
  print_person_info(student[I]);

                return 0;
}
void print_person_info(struct person clone)
{
  printf("Name = %s  %s, person.first_name, person.last_name");
  printf("Age    = %I, person.age");
}

void sort_by_age(int n, struct person a[])
{
     int I=0, j, temp;
  
     for(I=0; j<n-1;i++)
    {
      for(j=I+1;j<n;j++)
      { 
         if(student[I] > student[j])
         {
              temp =student[I];
              student[I]=student[j];
              student[j]=temp;
          }
       }
    }
}

When I use a struct, I work with the struct members using the dot operator.

To print out the five student records for instance, I'd use:

Code:

for(int i = 0; i < 5; i++) 
   printf("First name: %s  Last_name: %s  Age: %d n", student[i].first_name, student[i].last_name, student[i].age);

In your sorting function, you have a nice sort, except:

1) It's a Substitution sort - very similar to a bubble sort, but not quite the same.

2) You need to compare the student[i].age with student[j].age. And please, don't use uppercase i's because this I looks too much like 1.

Lowercase that i, please.

We have an excellent C tutorial link at the top middle portion of this website. You should spend some time there, and work through them. This is basic stuff, so you need to up your game to keep up with a class.