if is_open return false, do I have to close the file?

Question

In a code like this (from lesson 77), do I have always to close the file, or it could/should be closed only in the positive case?
Thanks in advance for your answer.

#include <iostream>
#include <fstream>
using namespace std;

int main() {
ofstream MyFile("test.txt");

if (MyFile.is_open()) {
MyFile << "This is awesome! \n";
}
else {
cout << "Something went wrong";
}
MyFile.close();
}

Answer 1

In the lesson 80 (Challenge 2) I see a similar code, where the file is closed only in positive case.

#include <iostream>
#include <fstream>
using namespace std;

int main() {
ofstream MyFile("test.txt");
if (MyFile.is_open()) {
MyFile << "This is awesome! \n";
MyFile.close();
}
else {
cout << "Something went wrong";
}
}

So I think it is not needed to close in negative (else) case the file, is it?

What happen if we close a file not opened?

Answer 2

Yes, it is not needed. You can try the code.