Why won't this code open the .txt files?

[idkwidlol]

#include <iostream>
#include <fstream>

using namespace std;

int main()

{
	cout << "Willkommen zu meinem Programm!\n\n";
	char choice;
	do {
		//User Prompt
		cout << "Please Choose a Selection from the Menu.\n\n";
		//Display Menu
		cout << "1) Program Languages and their uses\n2) Different Programming Paradigms\n3) Different C++ Features and their uses \n4) Exit\n\n";
		cin >> choice;
		cout << endl;
		if (choice == '1')
		{
			//Read the file
			ifstream infile;
			ofstream outfile;
			//Open the File
			infile.open("ProgrammingLanguages.txt", ios::in);
			//Ensure File exists
			if (!infile)
			{
				cout << "File does not exist!\n\n";
			}
			//Close the file
			infile.close();
		}
		if (choice == '2')
		{
			//Read the file
			ifstream infile;
			ofstream outfile;
			//Open the File
			infile.open("ProgrammingParadigms.txt", ios::in);
			//Ensure File exists
			if (!infile)
			{
				cout << "File does not exist!\n\n";
			}
			//Close the file
			infile.close();
		}
		if (choice == '3')
		{
			//Read the file
			ifstream infile;
			ofstream outfile;
			//Open the File
			infile.open("C++Features.txt", ios::in);
			//Ensure File exists
			if (!infile)
			{
				cout << "File does not exist!\n\n";
			}
			//Close the file
			infile.close();
		}
		else if (choice == '4')
		{
			//Tell user to have nice day
			cout << "A thousand blessings upon you and your family.\n";
			cin.get();
			cin.ignore();
	}

	} while (choice != '4');

	return 0;

}

[weaknessforcats]

In each of your menu choices you define an infile variable. When the closing brace occurs, the variable is now out of scope and can't be used any further in the program.

Just define one infile variable for the entire main() function.