#include <iostream>
#include <fstream>
#include <string>
 
using namespace std;
 
int main(){
 
    int choice;
 
    cout << "What do you want to do?\n";
    cout << "1) Write To File\n";
    cout << "2) Read From File\n";
    cout << "Enter a choice: ";
    cin >> choice;
 
 
    ofstream outputFile("file.txt", ios::app);
    ifstream inputFile;
 
        char myString[50];
 
    switch (choice){
 
        case 1:
 
    cout << "Enter a string: ";
    cin.get( myString, 50, '\n');
 
    cout << "Writting string to file...\n";
 
    outputFile << myString;
    outputFile.close();
 
    inputFile.open("file.txt");
 
    break;
 
        case 2:
 
    inputFile.open("file.txt");
 
    cout << "Reading string from file...\n";
 
    inputFile.getline(myString, 50, '\n');
 
    cout << myString;    
 
    break;    
 
        default:
            cout << "Not a valid choice!";
            break;
 
    }
 
    system("pause");
 
    return 0;
 
 
}

 cin

cin >> choice;
cin.ignore( 80, '\n' );

 
cin.ignore( 80, '\n' );

#include <string>
#include <sstream>
#include <iostream>
using namespace std;
 
int main ( ) {
    string input;
 
    if ( getline(cin,input) ) {
        istringstream convert(input);
        int result;
        if ( convert >> result ) {
            cout << "Success = " << result << endl;
        } else {
            cout << "Not an integer" << endl;
        }
    } else {
        cout << "No input" << endl;
    }
 
    return 0;
}