Split the program with libraries . c and . h

Question

Friends, I just made a program to calculate the transposed matrix. My question is: how can I turn this program into a function, so that I have two more files (one .c and one .h) besides main. c?! I hope you have understood my question. Below is my code in C:

int main(int argc, char *argv[]) {
int matriz_1[2][2];
int matriz_2[2][2];
int i, j;

matriz_1[0][0] = 1;
matriz_1[0][1] = 2;
matriz_1[1][0] = 3;
matriz_1[1][1] = 4;

for(i = 0;i < 2;i++) {
    for(j = 0;j < 2;j++) {
        matriz_2[j][i] = matriz_1[i][j];
    }
}

for(i = 0;i < 2;i++) {
    printf("[ ");
    for(j = 0;j < 2;j++) {
        printf("%d ", matriz_2[i][j]);
    }
    printf("]\n");
}

return 0;
}

Thank you!!

Answer 1

To divide into .c and .h simply create a role in the .h, and in the .c put all the code you have. Then it would only be necessary to call on main. That wouldn’t be a great idea but it would look like this:

matrix. h

#include <stdio.h>
#ifndef MATRIZ_H_INCLUDED
#define MATRIZ_H_INCLUDED

void programa_matriz();

#endif // MATRIZ_H_INCLUDED

matrix. c

#include "matriz.h"
void programa_matriz(){
    //todo o código que tinha no main aqui
}

main. c

#include "matriz.c"
int main(){
    programa_matriz();
    return 0;
}

Split functions by features

One of the ideas of separating into .h and .c is able to include the .h and use the functions you need for each separate feature. This means that it will hardly make sense to "turn a program into a function" but turn each functionality into a function thus giving as much reuse and organization as possible of the code.

In your case you could at least separate into two functions:

• invert matrix
• show matrix

Leaving the creation of matrices in the main even.

Example:

matrix. h

#include <stdio.h>
#ifndef MATRIZ_H_INCLUDED
#define MATRIZ_H_INCLUDED

void inverter_matriz(int matriz[2][2], int matriz_invertida[2][2]);
void mostrar_matriz(int matriz[2][2]);

#endif // MATRIZ_H_INCLUDED

matrix. c

#include "matriz.h"

void inverter_matriz(int matriz[2][2], int matriz_invertida[2][2]){
    int i, j;
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 2; j++) {
            matriz_invertida[j][i] = matriz[i][j];
        }
    }
}

void mostrar_matriz(int matriz[2][2]){
    int i, j;
    for(i = 0; i < 2; i++) {
        printf("[ ");
        for(j = 0; j < 2; j++) {
            printf("%d ", matriz[i][j]);
        }
        printf("]\n");
    }
}

main. c

#include <stdio.h>
#include "matriz.h"

int main(int argc, char *argv[]) {
    int matriz_1[2][2];
    int matriz_2[2][2];

    matriz_1[0][0] = 1;
    matriz_1[0][1] = 2;
    matriz_1[1][0] = 3;
    matriz_1[1][1] = 4;

    inverter_matriz(matriz_1, matriz_2);
    mostrar_matriz(matriz_2);

    return 0;
}