Problem in assembling a C matrix

Question

I have a problem with a matrix that I set up to be typed letters and these transformed into ascii table numbers, but it doesn’t print Where am I wrong? Someone can help me?

#include <stdio.h>
#include <stdlib.h>
int main(){
 char i, j, m[3][3];
 char tecla[0];


 //captura os elementos
 for(i=0;i<3;i++)
 for(j=0;j<3;j++){
 printf("Elemento[%d][%d]= ",i,j);
 tecla[0] = getche();
 scanf("%c",&m[i][j]);
 }
 //EXIBIR VALORES ORIGINAIS
 printf("\n::: Valores Originais :::\n");
 for(i=0;i<3;i++){
 for(j=0;j<3;j++)
 printf("%c ",m[i][j]);
 tecla[0] = getche();
 printf("\n");
 }

Answer 1

I think what you wanted was this:

#include <stdio.h>
#include <stdlib.h>
int main() {
    char i, j, m[3][3];
    char tecla;

    //captura os elementos
    for (i = 0; i < 3; i++) {
        for (j = 0; j < 3; j++) {
            printf("Elemento[%d][%d] = ", i, j);
            tecla = getche();
            scanf("%c", &m[i][j]);
         }
     }

     //EXIBIR VALORES ORIGINAIS
     printf("\n::: Valores Originais :::\n");
     for (i = 0; i < 3; i++) {
         for (j = 0; j < 3; j++) {
             printf("%c ", m[i][j]);
         }
         printf("\n");
     }
     tecla = getche();
}

Always use the { and the } to avoid making mistakes. For example, in this code you posted:

 //EXIBIR VALORES ORIGINAIS
 printf("\n::: Valores Originais :::\n");
 for(i=0;i<3;i++){
 for(j=0;j<3;j++)
 printf("%c ",m[i][j]);
 tecla[0] = getche();
 printf("\n");
 }

Note that the for from within has not the {. This makes the tecla[0] = getche(); and the printf("\n"); are out of the for internal. If you always use the { in all ties for, you won’t have this problem. Ideating everything properly will also help you a lot.

Moreover, char tecla[0]; declares an array of zero positions and you write at its first position (position 0), which is already outside the array. This doesn’t make sense, it’s easier to use just a common variable char tecla;.