Remove whitespace from input stream by only means of istream functions

Question

Is there any way of to remove the trailing whitespace after entered a decimal? E.g.:

10        A

I want to catch the first character after the whitespace ends. (Which gotta be \n to be true. if not, then false

My attempt so far:

cout << "Please enter a number: ";
cin >> n;

if (cin.peek() == ' ')
    //Something to catch the whitespaces

if(cin.fail() || cin.peek() != '\n')
    cout << "Not a number." << endl;

else
    cout << "A number." << endl;

Possible to do that by functions in istream?

(I know cin.fail can do good deeds, but it still doesn't consider an input of 10A as a fail)

Answer 1

Thanks for your help. With strings it do be easy yes. Though not allowed to use it.

Can be done by this simple method:

cout << "Please enter a number: ";
cin >> n;

while (cin.peek() == ' ')
   cin.ignore(1,' ');

if(cin.fail() || cin.peek() != '\n')
   cout << "Not a number." << endl;

else
   cout << "A number." << endl;