using System.Text.RegularExpressions;
using System;
class Validation
{
public static void Main()
{
String strToTest;
Validation objValidate=new Validation();
Console.Write("Enter a String to Test for Alphabets:");
strToTest=Console.ReadLine();
if(objValidate.IsAlpha(strToTest))
{
Console.WriteLine("{0} is Valid Alpha String",strToTest);
}
else
{
Console.WriteLine("{0} is not a Valid Alpha String",strToTest);
}
}
// Function to test for Positive Integers.
public bool IsNaturalNumber(String strNumber)
{
Regex objNotNaturalPattern=new Regex("[^0-9]");
Regex objNaturalPattern=new Regex("0*[1-9][0-9]*");
return !objNotNaturalPattern.IsMatch(strNumber) &&
objNaturalPattern.IsMatch(strNumber);
}
// Function to test for Positive Integers with zero inclusive
public bool IsWholeNumber(String strNumber)
{
Regex objNotWholePattern=new Regex("[^0-9]");
return !objNotWholePattern.IsMatch(strNumber);
}
// Function to Test for Integers both Positive & Negative
public bool IsInteger(String strNumber)
{
Regex objNotIntPattern=new Regex("[^0-9-]");
Regex objIntPattern=new Regex("^-[0-9]+$|^[0-9]+$");
return !objNotIntPattern.IsMatch(strNumber) &&
objIntPattern.IsMatch(strNumber);
}
// Function to Test for Positive Number both Integer & Real
public bool IsPositiveNumber(String strNumber)
{
Regex objNotPositivePattern=new Regex("[^0-9.]");
Regex objPositivePattern=new Regex("^[.][0-9]+$|[0-9]*[.]*[0-9]+$");
Regex objTwoDotPattern=new Regex("[0-9]*[.][0-9]*[.][0-9]*");
return !objNotPositivePattern.IsMatch(strNumber) &&
objPositivePattern.IsMatch(strNumber) &&
!objTwoDotPattern.IsMatch(strNumber);
}
// Function to test whether the string is valid number or not
public bool IsNumber(String strNumber)
{
Regex objNotNumberPattern=new Regex("[^0-9.-]");
