How can i return an entire array from a function into the main function after i call it?In C program?

In general, it's a pain in C. C needs to have "compile time" knowledge about the dimensions of a matrix or else it cannot automatically calculate the addresses given the indices and simply doesn't know what to do. So the question comes down to whether or not your matrices are of fixed size. If you imagine the first index as a row and the second index as a column, C needs to at least know the number of columns. You can create a varying number of rows, then. But not a varying number of columns. If you want both to be varying, then you need to return the matrix as a simple vector and do all the indexing calculations using explicit formulas in your code. (This is part of the reason why some people have created general-purpose matrix libraries for C. These will provide structures that include the necessary information to manage the matrices.) Assume you are just returning fixed sized matrices where both dimensions are always known at compile time. Then: int (*my5x10( void ))[5][10] {     return (int (*)[5][10]) malloc( 50 * sizeof(int) ); } will allocate the matrix on the heap and return a pointer to it. Note the somewhat arcane syntax. But it reads "a function called my5x10 that takes void as parameters and returns a pointer to a 5x10 array of integers." You will have to later free that matrix, elsewhere, since it was allocated on the heap. You cannot write this, safely: int (*my5x10( void ))[5][10] {     int myarray[5][10];     return &myarray; } The local array won't be valid as soon as the function returns (under some operating systems anyway), so the matrix made that way is useless to the calling routine. That's why you need the heap. (Or else some static lifetime matrix.) So you could say: int (*my5x10( void ))[5][10] {     static int myarray[5][10];     return &myarray; } You can return structures from functions. So you could put the matrix into a structure and then return it. But as the above shows already, you cannot return the matrix without a structure wrapper or as a pointer to the matrix. Never the matrix itself. The syntax doesn't support it. So: typedef struct { int arr[5][10]; } matrix5x10_t; matrix5x10_t myfunc( void ) {     stupid_t x;     return x; } Would work. This forces the compiler to pass in a hidden pointer (usually) from the caller that is a pointer to its receiving structure and the function uses that, either directly or else at the end by performing a copy operation from the local variable into the caller's. (Optimization may eliminate that copy step.) If you need variable sized matrices, both dimensions, then you need to do your own calculations and instead use an array and break it up into rows using your own formula to do so.

arrays are passed to functions as address/pointer and they are returned the same way an array declared locally inside the function can not be returned unless it is declared as static. You are actually return the address of the array int **func(....) { static int result[666][999]; ... code here ... return result; } if you do this without it being static you return garbage that is written over

Here is an example to play and test: #include <iostream> using namespace std; int** devueveArray2(int dimX, int dimY) { int **arr = new int*[dimX]; for(int i=0; i<dimX; ++i) { arr[i] = new int[dimY]; } for(int i=0; i<dimX; ++i) for(int j=0; j<dimY; ++j) arr[i][j] = dimY*i+j; return arr; } int main() { int dimX, dimY; cout << "ingresa las filas y columnas: "; cin >> dimX >> dimY; int **a = devueveArray2(dimX, dimY); for(int i=0; i<dimX; ++i) { for(int j=0; j<dimY; ++j) { cout << a[i][j] << "\t"; } cout << "\n"; } for(int i=0; i<dimX; ++i) delete[] a[i]; delete[] a; return 0; }

arrays are passed to functions as address/pointer and they are returned the same way an array declared locally inside the function can not be returned unless it is declared as static. You are actually return the address of the array int **func(....) { static int result[666][999]; ... code here ... return result; } if you do this without it being static you return garbage that is written over

Here is an example to play and test: #include <iostream> using namespace std; int** devueveArray2(int dimX, int dimY) { int **arr = new int*[dimX]; for(int i=0; i<dimX; ++i) { arr[i] = new int[dimY]; } for(int i=0; i<dimX; ++i) for(int j=0; j<dimY; ++j) arr[i][j] = dimY*i+j; return arr; } int main() { int dimX, dimY; cout << "ingresa las filas y columnas: "; cin >> dimX >> dimY; int **a = devueveArray2(dimX, dimY); for(int i=0; i<dimX; ++i) { for(int j=0; j<dimY; ++j) { cout << a[i][j] << "\t"; } cout << "\n"; } for(int i=0; i<dimX; ++i) delete[] a[i]; delete[] a; return 0; }