isupper()

Prototype: int isupper (int c);
Header File: ctype.h (C) or cctype (C++)
Explanation: Tests to see if the ASCII character associated with the integer c is an uppercase letter.

#include <iostream>
#include <cctype>

using namespace std;

//Example reads in a character and tests if it uppercase
int main()
{
    char x;
    cin>>x;
    if(isupper(x))
    {
        cout<<"Uppercase";
    }
    else
    {
        cout<<"Not uppercase.";
    }
}

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