Tests to see if a string contains only letters. - CSharp System

CSharp examples for System:String Contain

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Description

Tests to see if a string contains only letters.

Demo Code

//  Copyright ? 2011, Grid Protection Alliance.  All Rights Reserved.
using System.Text.RegularExpressions;
using System.Text;
using System.IO;//w  ww.  j a va 2 s. c  o m
using System.Globalization;
using System.ComponentModel;
using System.Collections.Generic;
using System;

public class Main{
        /// <summary>
        /// Tests to see if a string contains only letters.
        /// </summary>
        /// <param name="value">Input string.</param>
        /// <param name="ignorePunctuation">Set to True to ignore punctuation.</param>
        /// <returns>True, if all string's characters are letters; otherwise, false.</returns>
        public static bool IsAllLetters(this string value, bool ignorePunctuation)
        {
            if (string.IsNullOrEmpty(value))
                return false;

            value = value.Trim();
            if (value.Length == 0)
                return false;

            for (int x = 0; x < value.Length; x++)
            {
                if (ignorePunctuation)
                {
                    if (!(char.IsLetter(value[x]) || char.IsPunctuation(value[x])))
                        return false;
                }
                else
                {
                    if (!char.IsLetter(value[x]))
                        return false;
                }
            }

            return true;
        }
        /// <summary>
        /// Tests to see if a string contains only letters.
        /// </summary>
        /// <param name="value">Input string.</param>
        /// <returns>True, if all string's characters are letters; otherwise, false.</returns>
        /// <remarks>Any non-letter character (e.g., punctuation marks) causes this function to return false (See overload to ignore punctuation
        /// marks.).</remarks>
        public static bool IsAllLetters(this string value)
        {
            return value.IsAllLetters(false);
        }
}

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