Structure and file processing

Structure
Structure is a data type used to store a group of data. It is user defined and the group of data can be varied.
Structure declaration :
struct name_structure{
   data_type name
   ...
};

Example :
struct mahasiswa{
   int NIM;
   char nama[21];
   char jurusan[51];
}agus;

To call an element of a structure, use dot operator : agus.NIM
Structure can also be used in conjunction with array. To declare structrure with array, just declare it as usual.

struct mahasiswa{
   int NIM;
   char nama[21];
   char jurusan[51];
}data[20];

Example of storing structured array:
void storeStruct(){
   struct mahasiswa{
      int NIM;
      char nama[21];
      char jurusan[51];
   }data[20];

   

   int i;

   for(i = 0; i < 20; i++){

        scanf("%d", &data[i].NIM);

        scanf("%[^\n]", &data[i].nama);

        getchar();

        scanf("%[^\n]", &data[i].jurusan);

        getchar();   

   }

}

File Processing

To open a file in C, you need a pointer in your program. In C, they use File *name for using file.

Example : File *fin 

There are several mode in C, but the most common are :

- w, create a file/overwrite a file

- r, read a file

- a, to modify a file

The function for file processing is the same as others, except you add f in front of the function(fscanf,fprintf).

There are 3 steps in processing a file :

- Opening the file

   File *fin = ("file name", "mode");

   Example = File *fin = ("textdata.in", "r");

- Processing the file

   Example of reading file

int x;

   while(!feof(fin)){

        fscanf(fin, "%d\n", &x);

   }

- Closing the file

   fclose(fin);