visual studio 2010 - Check for non-numeric inputs in a C++ program -

how check non-numeric input using c++? using cin read in float value, , want check if non-numerical input entered via stdin. have tried use scanf using %d designator, output corrupted. when using cin, correct format, when enter, string such "dsffsw", infinite loop. commented code attempt capture float, , type cast string, , check if valid float, check comes false.

i have tried using other methods have found on message boards, want use scanf in c , not cin in c++. how do in c++? or in c if not feasible.

while (!flag) {         cout << "enter amount:" << endl;         cin >> amount;       cout << "begin amount entered is: " << strtod(&end,&pend) << endl;          //if (!strtod(((const char *)&amount), null))   {         //  cout << "this not float!" << endl;         //  cout << "i = " << strtod(((const char *)&amount), null) << endl;         //  //amount = 0.0;         //}          change = (int) ceil(amount * 100);          cout << "change = " << change << endl;          cout << "100s= " << change/100 << endl;         change %= 100;         cout << "25s= " << change/25 << endl;         change %= 25;         cout << "10s= " << change/10 << endl;         change %= 10;         cout << "5s= " << change/5 << endl;         change %= 5;         cout << "1s= " << change << endl;         cout << "end amount entered is: " << amount << endl; } return 0; 

}

int amount;  cout << "enter amount:" << endl;  while(!(cin >> amount)) {    string garbage;    cin.clear();    getline(cin,garbage);    cout << "invalid amount. "         << "enter numeric value amount:" << endl; }