Security Data Input in C++

[athila]

Hello Everybody...

I'm trying to write a code for input a int data in a security way. If the user enter with a letter, an error message could be showed.

My code is the following:

#include <iostream>
using namespace std;

int main(){
int a;


do {
cout << "Enter the value of a: ";
cin >> a;
if (cin.fail()){
cout << "You put an invalid value, try again" << endl;
cin.ignore(); //I've already tried cin.clear();
}
}while(cin.fail());

return 0;
}

When I run my code and enter with a letter, the program execute in an infinite loop. I'll be happy, if somebody can help me.

Thanks

Áthila

[dailei]

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

int main()
{
int a;

do
{
cout << "Enter the value of a: ";
cin >> a;
if (cin.fail())
{
cout << "You put an invalid value, try again" << endl;
cin.clear();
string s;
cin>>s;
}
else
break;
}while (true);
cout<<"quit!"<<endl;
return 0;
}