check if the user enters a number instead of a letter

•

What is DaniWeb IT Discussion Community?

You're currently browsing the C++ section within the Software Development category of DaniWeb, a massive community of 397,813 software developers, web developers, Internet marketers, and tech gurus who are all enthusiastic about making contacts, networking, and learning from each other. In fact, there are 2,571 IT professionals currently interacting right now! Registration is free, only takes a minute and lets you enjoy all of the interactive features of the site.

Join our community!

Please support our C++ advertiser:

Thread Tools Display Modes

Views: 4699 | Replies: 3

•

Join Date: May 2007

Posts: 2

Reputation: manny c++ is an unknown quantity at this point

Rep Power: 0

Solved Threads: 0

manny c++

Offline

Newbie Poster

check if the user enters a number instead of a letter

May 15th, 2007

Hi all

I have fingered out how to check the users input for their first and last name
This works fine.

If the user enters a number for their name they resave an error message.
But it only works for the first letter

How do I increment the check for each additional letter

Help with Code Tags

(Toggle Plain Text)

 
int mainMenu::getName()
{
    int i;
 
    cout << "\tPlease enter your first name: ";
    cin.get(firstName, 20).get();
 
    while (isdigit(firstName[i]))
    {
        printf("\n\t\a%c[%d;%dmYou entered a Number ", 0x1B, BRIGHT, RED, BG_BLACK);
        printf("%c[%dm", 0x1B, 0);
        cout << firstName;
        cout << flush;
 
        printf(", %c[%d;%dmAs part of your first Name try agin.\n\n", 0x1B, BRIGHT, RED, BG_BLACK);
        printf("%c[%dm", 0x1B, 0);
 
        cout << "\tPlease enter your firstName: ";
        cin.get(firstName, 20).get();
        cout << endl;
    }
 
    cout << endl;
    cout << "\tPlease enter your lastName: ";
    cin.get(lastName, 20).get();
 
    while (isdigit(lastName[i]))
    {
        printf("\n\t\a%c[%d;%dmYou entered a Number ", 0x1B, BRIGHT, RED, BG_BLACK);
        printf("%c[%dm", 0x1B, 0);
        cout << lastName;
        cout << flush;
 
        printf(", %c[%d;%dmEnter your last name try agin.\n\n", 0x1B, BRIGHT, RED, BG_BLACK);
        printf("%c[%dm", 0x1B, 0);
 
        cout << "\tPlease enter your lastName: ";
        cin.get (lastName, 20).get();
    }
 
    firstName[0] = toupper (firstName[0]);
    lastName[0] = toupper (lastName[0]);
 
    cout << endl;
 
    return 0;
 
}

Thank you,
manny

•

Join Date: Apr 2007

Posts: 102

Reputation: mariocatch is an unknown quantity at this point

Rep Power: 2

Solved Threads: 17

mariocatch mariocatch is offline

Offline

Junior Poster

Re: check if the user enters a number instead of a letter

May 15th, 2007

Help with Code Tags

(Toggle Plain Text)

#include<iostream>
usingnamespace std;
#include<string>
 
int main()
{char y;
 
cout << "Enter a character or number: _\b";
cin >> y;
 
if(!isdigit(y))cout << "It's a Letter";
elsecout << "It's a Number";
cout << '\n';
 
return 0;
}

•

Join Date: Dec 2006

Posts: 1,296

Reputation: Aia is a name known to all

Rep Power: 9

Solved Threads: 88

Aia

Offline

Nearly a Posting Virtuoso

Re: check if the user enters a number instead of a letter

May 16th, 2007

•

Originally Posted by mariocatch

Help with Code Tags

(Toggle Plain Text)
#include<iostream>
usingnamespace std;
#include<string>
 
int main()
{char y;
 
cout << "Enter a character or number: _\b";
cin >> y;
 
if(!isdigit(y))cout << "It's a Letter";
elsecout << "It's a Number";
cout << '\n';
 
return 0;
}
#include<iostream> usingnamespace std; #include<string> int main() {char y; cout << "Enter a character or number: _\b"; cin >> y; if(!isdigit(y))cout << "It's a Letter"; elsecout << "It's a Number"; cout << '\n'; return 0; }

My friend, I think you are assuming too much of that if statement. What if the entered input is a space or a new line or " ?. Would that be considerate a letter?.

Last edited by Aia : May 16th, 2007 at 12:03 am.

"No man's life, liberty, or property is safe while the legislature is in session." ~ Mark Twain

•

Join Date: May 2007

Posts: 2

Reputation: manny c++ is an unknown quantity at this point

Rep Power: 0

Solved Threads: 0

manny c++

Offline

Newbie Poster

Re: check if the user enters a number instead of a letter

May 16th, 2007

•

Originally Posted by Aia

My friend, I think you are assuming too much of that if statement. What if the entered input is a space or a new line or " ?. Would that be considerate a letter?.

Hi

Thank you but I am asking the user to enter their name. And confirm that a letter has ban entered if not output a message I have the first part worked out

If the first letter is a digit the user resaves a message

I am trying to increment this processes for each character entered by one.

Help with Code Tags

(Toggle Plain Text)

 
while (isdigit(firstName[i]))
{
    printf("\n\t\a%c[%d;%dmYou entered a Number ", 0x1B,    BRIGHT, RED, BG_BLACK);
    printf("%c[%dm", 0x1B, 0);
    cout << firstName;
    cout << flush;
 
    printf(", %c[%d;%dmAs part of your first Name try agin.\n\n",  0x1B, BRIGHT, RED, BG_BLACK);  
    printf("%c[%dm", 0x1B, 0);
 
    cout << "\tPlease enter your firstName: ";
    cin.get(firstName, 20).get();
    cout << endl;
}

Last edited by cscgal : May 16th, 2007 at 8:28 pm. Reason: Excessive color removed per forum policy