OOP

[pmah]

I am a new first semester student. I wanted to work with OOP. I have a question, how can I make one class function accessible by another ? Below is my code:

#include <iostream>
#include <fstream>
using namespace std;
#include <filesystem>
namespace fs = std::filesystem;

// Class to define the properties
class File {
public:

	// Function declaration of input() to input info
	void input();

	
	//Copy the file read by input()
	void output();
};

// Function definition of input() to input info
void File::input()
{
	
	const std::filesystem::path src = "Input.txt";
	cout<<"File copied";
	
}

// Function output() to save the file to destination
void File::output()
{
	const std::filesystem::path dst = "Hello.txt";
	//But here source wont be accessible
    	std::filesystem::copy_file(src, dst, std::filesystem::copy_options::overwrite_existing);
		

	// Output is the stored file
	cout << "\nFile stored"<<endl;
}

// Driver code
int main()
{
	// Creating object of the class
	File object;

	// Copying source file contents
	
	object.input();

	//Outputting data means saving it in a file. 
	object.output();

	return 0;
}

I want input() to be accessible by output(). How can we do that

[Peter87]

You mean you want to call input() from output()? If that is what you want you just write the function name followed by parentheses without anything in front.

void File::output()
{
	input();
}

[pmah]

I get the error:
‘src’ was not declared in this scope

[seeplus]

The issue is that src is defined locally in function input() - so can't be used in function output(). Perhaps make src a member variable? Perhaps:

#include <iostream>
#include <fstream>
using namespace std;
#include <filesystem>
namespace fs = std::filesystem;

// Class to define the properties
class File {
public:
	// Function declaration of input() to input info
	void input();

	//Copy the file read by input()
	void output();

private:
	std::filesystem::path src;
};

// Function definition of input() to input info
void File::input() {
	src = "Input.txt";
}

// Function output() to save the file to destination
void File::output() {
	const std::filesystem::path dst = "Hello.txt";

	std::filesystem::copy_file(src, dst, std::filesystem::copy_options::overwrite_existing);

	// Output is the stored file
	cout << "\nFile stored\n";
}

// Driver code
int main() {
	// Creating object of the class
	File object;

	object.input();

	//Outputting data means saving it in a file.
	object.output();
}