i wanted to take input of letters only but its not working properly. if i input a random string like abcd123 it repeats try again when i enter again same abcd123 it will output ignoring the condition i want this only to take abcd.

#include <iostream>
#include <string>
using namespace std;

bool IsLetters(string &input)
{
 for (int i = 0; i < input.size(); i  )
 {   
     int uppercaseChar = toupper(input[i]); //condition for letters
     if (uppercaseChar < 'A' || uppercaseChar > 'Z') 
     {   cout<<"try again\n";
        cin>>input;
         return IsLetters;
     }
 }

 return true; 
}


int main() 
{
 string x;
 cout<<"enter your name\n";
 cin>>x; //string input
 if (IsLetters(x)) // function call
 {
     cout << "your name is\n"<<x;
 }
 
 return 0;
}

CodePudding user response：

you need to change logic, pls try following

#include <iostream>
#include <string>
using namespace std;

    bool IsLetters(string& input)
    {
        for (int i = 0; i < input.size(); i  )
        {
            int uppercaseChar = toupper(input[i]); //condition for letters
            if (uppercaseChar < 'A' || uppercaseChar > 'Z')
            {
                return true;
            }
        }
    
        return false;
    }
    
    
    int main()
    {
        string x;
        cout << "enter your name\n";
        cin >> x; //string input
    
        while (IsLetters(x)) // function call
        {
            cout << "try again\n";
            cin >> x;
        }
        cout << "your name is\n" << x;
        return 0;
    }

CodePudding user response：

You can try this straightforward solution.

    #include <iostream>
    #include <string>
    using namespace std;
    int main() {
        string s;
        cout <<"enter your name\n";
        cin >> s;
        int flag = false;
    
        while (flag != true)
        {
            for (int i = 0; i < s.size(); i  )
            {
                if (!(s[i] >= 'A' && s[i] <= 'Z') &&  !(s[i] >= 'a' && s[i] <= 'z'))
                {
                    flag  = true;
                    break;
                }
            } 
    
            if (flag == true)
            {
                cout<<"try again\n";
                flag  = false;
                cin >> s;
            } else {
                cout << s;
                break;
            }
        }
    
        return 0;
    }