c do while döngüsü kullanımı:

do while döngüsünd kod bloğu ilk olarak işlenir daha sonra koşul sağlanıyorsa devam eder.

#include <stdio.h>

int main()
{
    int count, sayi = 1, not, toplam, ortalama; 

    toplam = 0; 
    printf( "Girilecek sayı adetini giriniz: " ); 
    scanf( "%d", &count );
    
   do{
       printf( "%d. sayi : ",sayi ); 
       scanf( "%d", &not );
       toplam = toplam + not;
       sayi = sayi + 1; 
   } while ( sayi <= count ) ;
    ortalama = toplam / count;
    printf( "Sınıf ortalaması %d dir.\n", ortalama );
    return 0;
}

çıktı:

Girilecek sayı adetini giriniz: 3                                                                                                                                                  

1. sayi : 2                                                                                                                                                                        

2. sayi : 3                                                                                                                                                                        

3. sayi : 4                                                                                                                                                                        

Sınıf ortalaması 3 dir.