C code skipping user input

Question

Hello! I am Newbie and I am trying to make a program to read a list of information inserted in it. Until the first line it works, but from the second register he no longer reads the name, putting the second text "SEXO: [M/F]" in the name line and the end result does not exit as expected.

Follows the code:

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

int main (void) {
    setlocale(LC_ALL, "Portuguese");

    // <.Listagem de Cadastrados.>

    char nome1[40], nome2[40], nome3[40];
    char sexo1,sexo2, sexo3;
    float nota1,nota2,nota3;

    printf("Cadastrando 1° pessoa\n");
    printf("--------------------------\n");
    fflush(stdin);
    printf("NOME: ");
    fgets(nome1,40,stdin);
    printf("SEXO [M/F]: ");
    sexo1 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota1);
    printf("--------------------------\n");

    printf("Cadastrando 2° pessoa\n");
    printf("--------------------------\n");
    fflush(stdin);
    printf("NOME: ");
    fgets(nome2,40,stdin);
    printf("SEXO [M/F]: ");
    sexo2 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota2);
    printf("--------------------------\n");

    printf("Cadastrando 3° pessoa\n");
    printf("--------------------------\n");
    fflush(stdin);
    printf("NOME: ");
    fgets(nome3,40,stdin);
    printf("SEXO [M/F]: ");
    sexo3 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota3);

    system("clear"); // limpar tela - mesma ideia do cls no windows.

    printf("Listagem Completa\n\n");
    printf("------------------------------\n");
    printf("NOME SEXO NOTA");
    printf("%s %c %.2f\n",nome1,sexo1,nota1);
    printf("%s %c %.2f\n",nome2,sexo2,nota2);
    printf("%s %c %.2f\n",nome3,sexo3,nota3);
    printf("------------------------------\n");
}

Could you help me understand this problem? Could suggest improvements in code?

Att.

Answer 1

The problem is with scanf(), it reads a float and leaves an empty line in the buffer, so when you use fgets() it reads this empty line.

Only to clean the buffer you used fflush(stdin), which is not recommended and even avoided, so do not use it.

One solution I found was to add a getchar() after each scanf() to read this empty line and the code no longer ignores the entries.

So the code went like this:

#include <stdio.h>
#include <locale.h>
#include <stdlib.h>
int main (void) {
    setlocale(LC_ALL, "Portuguese");

    // <.Listagem de Cadastrados.>

    char nome1[40], nome2[40], nome3[40];
    char sexo1,sexo2, sexo3;
    float nota1,nota2,nota3;


    printf("Cadastrando 1° pessoa\n");
    printf("--------------------------\n");
    printf("NOME: ");
    fgets(nome1,40,stdin);
    printf("SEXO [M/F]: ");
    sexo1 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota1);
    getchar();

    printf("--------------------------\n");

    printf("Cadastrando 2° pessoa\n");
    printf("--------------------------\n");
    printf("NOME: ");
    fgets(nome2,40,stdin);
    printf("SEXO [M/F]: ");
    sexo2 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota2);
    getchar();

    printf("--------------------------\n");

    printf("Cadastrando 3° pessoa\n");
    printf("--------------------------\n");
    printf("NOME: ");
    fgets(nome3,40,stdin);
    printf("SEXO [M/F]: ");
    sexo3 = getchar();
    printf("NOTA: ");
    scanf("%f", &nota3);
    getchar();

    system("clear"); // limpar tela - mesma ideia do cls no windows.

    printf("Listagem Completa\n\n");
    printf("------------------------------\n");
    printf("NOME SEXO NOTA\n");
    printf("%s %c %.2f\n",nome1,sexo1,nota1);
    printf("%s %c %.2f\n",nome2,sexo2,nota2);
    printf("%s %c %.2f\n",nome3,sexo3,nota3);
    printf("------------------------------\n");
}