c++ print/ build 2d array - c++

Question

I'm trying to build and print a 2d array but its showing up as empty when I try to print it out so there's an error somewhere but I cant find it. Can someone help? I added the code for initializing the array.
#ifndef MAZE_HPP_
#define MAZE_HPP_
#include <fstream>
#include <vector>
#include <string>
class Maze
{
public:
Maze(int size);
~Maze() {}
enum Direction { DOWN, RIGHT, UP, LEFT };
// Implement the following functions:
// read maze from file, find starting location
void readFromFile(std::ifstream &f);
// make a single step advancing toward the exit
void step();
// return true if the maze exit has been reached, false otherwise
bool atExit();
// set row and col to current position of 'x'
void getCurrentPosition(int &row, int &col);
//print function
void printMaze();
// You can add more functions if you like
private:
// Private data and methods
int size, rowX, colY;
char matrix[30][30];
};
#endif /* MAZE_HPP_ */
void Maze::readFromFile(std::ifstream &f) {
std::string line;
int i, j;
getline(f, line);
for(i = 0; i < size; i++) {
getline(f, line);
for(j = 0; j < size; j++) {
matrix[j][i] = line[j];
}
}
f.close();
}
void Maze::printMaze() {
int i, j;
for(i = 0; i < size; i++) {
for(j = 0; j < size; j++) {
std::cout << matrix[i][j] << "";
std::cout << "line";
}
std::cout << std::endl;
}
}

Answer 1

The initialization does not matter here although it is good practice. Back to the problem: there can be several reasons
1. You have passed zero or negative number for size in the constructor when you create a Maze object.
2. You have passed positive number for size but forgot to assign it to the size variable in the constructor.
If it enters into the loop in print function and shows the string "line" size times then it means it can not read anything from file.
It would be helpful if you send full code or at least the constructor.