C++ How to read first character from users input and ignore rest (char type)

Question

char Oprt;
cout << "\nPlease enter first number: ";
cin >> num1;
cout << "Please enter second number: ";
cin >> num2;
cout << "Now please enter operator: ";
cin >> Oprt;
while (Oprt != '+' && Oprt != '-' && Oprt != '*' && Oprt != '/')
{
    cout << "Wrong Operator please enter again: ";
    cin >> Oprt;
}

When user writes something like 'ffsd' as input the loop cycles for as much times as there are characters written by user but what I want is my program to read only first symbol and ignore the rest.

I don't really think the "game-engine" tag is relevant.

George
– George

2017-03-20 16:31:31 +00:00
Commented Mar 20, 2017 at 16:31 — George
– George, Commented Mar 20, 2017 at 16:31

Sergey Kalinichenko · Accepted Answer · 2017-03-20 16:39:51Z

3

You have two valid approaches here:

Use cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n') to ignore all characters up to and including '\n', or
Use istream::getline to read a whole std::string, and then grab the initial character if the string is not empty.

In both cases you need to ignore the '\n' before entering the loop, because cin >> num2 does not remove '\n' from the input stream.

answered Mar 20, 2017 at 16:39

Sergey Kalinichenko

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Comments

Alexander Lapenkov · Accepted Answer · 2017-03-20 16:39:37Z

0

You can use std::istream::ignore. For example, like that.

std::cin.ignore(MAX_INPUT_LENGTH,'\n');

For more info, look in the reference

answered Mar 20, 2017 at 16:39

Alexander Lapenkov

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