Bug when user input more than a character with char variable - c++

Question

i'm making simple program to show "True" if user input 'z' and show "False" if user input anything else.
However, the problem is when user input more than a character, such as when user input 'zz' the output is
True
Input : True
and when user input such as 'zs' which should be wrong, the output is
True
Input : Wrong
Here's my code
#include <iostream>
using namespace std;
int main()
{
char input;
cout << "Check input" << endl;
while(true){
cout << "Input : ";
cin >> input;
if(input=='z'){
cout << "True" << endl;
} else {
cout << "Wrong" << endl;
}
}
return 0;
}
I wonder if there are ways to prevent this without change variable type to string?
I use CodeBlocks 16.04 (MinGW) with GNU GCC Compiler on Windows 10 x64

Answer 1

You cannot do that by reading single chars. The point is that if the user enters e.g. zz he actually did enter those two chars and these are the chars you are getting when you read from cin.
Just read a std::string as suggested and check only the first character of the string. That's just as simple that what you're doing.
So you probably want this:
#include <iostream>
#include <string>
using namespace std;
int main()
{
string input;
cout << "Check input" << endl;
while (true) {
cout << "Input : ";
cin >> input;
if (input.length() > 0 && input[0] == 'z') {
cout << "True" << endl;
}
else {
cout << "Wrong" << endl;
}
}
return 0;
}

Answer 2

Its definitely possible you just have to check the first character and make sure It is the only character entered than flush the buffer to get rid of the rest of the string.
code:
#include <iostream>
#include <string>
using namespace std;
int main()
{
char input;
cout << "Check input" << endl;
while (true) {
cout << "Input : ";
cin >> input;
//Check if the input is z and there is only 1 character inputted
if (cin.rdbuf()->in_avail() == 1 && input == 'z') {
cout << "True" << endl;
}
else {
cout << "Wrong" << endl;
}
//Flush the buffer
cin.clear();
cin.ignore(INT_MAX, '\n');
}
return 0;
}