Average is not being stored-C

Question

Good night!

When running the program and reporting the data Name, Nota1 and Nota2, the program is expected to create a file called "class.txt" with the student’s name, grades and average.

However my problem is reading the average correctly, when opening txt, the average is always 0.00. I wonder how to correct this error.

Thank you.

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

struct
{
    char nome[50];
    float nota1, nota2,media;

}aluno [10];



int main()
{
FILE *arq;
int j;
float media;

    for(j=0; j<10; j++)
    {
        printf("\n \t Dados do aluno %d", j+1);

        printf("\n\n Nome: ");
        scanf("%s", aluno[j].nome);
        fflush(stdin);

        printf("\n Nota 1: ");
        scanf ("%f", &aluno[j].nota1);

        printf("\n Nota 2: ");
        scanf ("%f", &aluno[j].nota2);
    }

    for (j=0; j<10; j++);
    {
        aluno[j].media=((aluno[j].nota1)+(aluno[j].nota2))/2;

    }
    printf("\n\n");
    printf("\t Calculando medias e criando arquivo.....");
    printf("\n");


    arq = fopen("turma.txt","w");

    for (j=0; j<10; j++)
    {

        fprintf(arq,"\n \t Dados do aluno %d \n", j+1);

        fprintf(arq,"\n\n Nome: %s, ",aluno[j].nome);

        fprintf(arq,"%.2f, ", aluno[j].nota1);

        fprintf(arq,"%.2f; ", aluno[j].nota2);

        fprintf(arq,"%.2f \n", aluno[j].media);

    }
    fclose(arq);
    system("cls");
    system("pause");

}

Answer 1

Gustavo, in your code you are iterating 2 times unnecessarily.

I took the loop that calculates the average and put inside the for that makes the readings of the notes.

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

struct {
    char nome[50];
    float nota1, nota2, media;
} aluno[10];

int main() {

    FILE *arq;
    int j; 
    float media;
    int total_aluno = 2; 

    for(j=0; j<total_aluno; j++) {
        printf("\n \t Dados do aluno %d", j+1);

        printf("\n\n Nome: ");
        scanf("%s", &aluno[j].nome);
        fflush(stdin);

        printf("\n Nota 1: ");
        scanf ("%f", &aluno[j].nota1);

        printf("\n Nota 2: ");
        scanf ("%f", &aluno[j].nota2);
        // Calculando as médias aqui 
        aluno[j].media = (aluno[j].nota1 + aluno[j].nota2)/2;
    }

    printf("\n\n");
    printf("\t Calculando medias e criando arquivo.....");
    printf("\n");

    arq = fopen("turma.txt","w");

    for (j=0; j<total_aluno; j++) {

        fprintf(arq,"\n \t Dados do aluno %d \n", j+1);

        fprintf(arq,"\n\n Nome: %s, ",aluno[j].nome);

        fprintf(arq,"%.2f, ", aluno[j].nota1);

        fprintf(arq,"%.2f; ", aluno[j].nota2);

        fprintf(arq,"%.2f \n", aluno[j].media);

    }
    fclose(arq);
    system("cls");
    system("pause");
}

I found the error quite strange, but it seems to me something with the variable reference.

Answer 2

Before the fclose(arq); call the fflush(arq);