Thread: Validation Program

How can i make a program which accept only the following:

1) Any positive number.
2)Character from [A to Z] -in upper case.

Note: this program won't work as desired because idon't know how to get the ASCII of any number or character-by using int().

Code:

#include<iostream.h>
void main()
{
int a;
cout<<"Enter either number or character to check it's availability "<<endl;

cin>>a;

if(int ('a')>=65 && int('a')<=90) // int('a') always will be 97-the ASCII of character a.
cout<<"It's valid"<<endl;
}

use ctype.h library functions.
check these out:
isalpha(),islower(),isdigit(),isupper()

Originally Posted by Echooo

Code:

if(int ('a')>=65 && int('a')<=90) // int('a') always will be 97-the ASCII of character a.
cout<<"It's valid"<<endl;

You said it yourself... 'a' is the ASCII character of the english letter A in lowercase... and int('a') is the numerical ASCII representation. You don't want to be using either, because ASCII values are constants.

on the other hand, a (without quotes) is your variable - so get rid of those single quotes. Also, you don't need the cast, because your variable a is already an int.

Code:

if( (a>=65) && (a<=90) ) //...

Originally Posted by SlyMaelstrom

Integers don't accept characters.

That's not quite true - characters are just a representation of an integer. The difference is how cin and cout will interpret the integer.

Code:

#include <iostream>
using namespace std;

int main()
{
    int x('c');
    cout << x << endl;
    cout << char(x) << endl;
    cin.get();
}