Check palindrome

Sandhiya Priya
21h
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Article

Step 1: Design Page – PalindromeString.aspx

  
    <%@ Page Language="C#" AutoEventWireup="true" CodeFile="PalindromeString.aspx.cs" Inherits="PalindromeString" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Palindrome String Checker - Real Time Example</title>
    <style>
        body {
            font-family: Arial;
            background-color: #f0f2f5;
            margin: 50px;
        }
        .container {
            width: 460px;
            margin: auto;
            background: white;
            border-radius: 8px;
            box-shadow: 0px 0px 10px #ccc;
            padding: 25px;
        }
        h2 {
            color: #1A2A80;
            text-align: center;
        }
        .form-control {
            width: 100%;
            padding: 8px;
            margin-top: 10px;
        }
        .btn {
            background-color: #7A85C1;
            color: white;
            border: none;
            padding: 10px 20px;
            margin-top: 10px;
            border-radius: 5px;
            cursor: pointer;
            width: 100%;
        }
        .result {
            margin-top: 20px;
            font-weight: bold;
            color: #333;
            text-align: center;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
        <div class="container">
            <h2>Palindrome String Checker</h2>

            <asp:Label ID="lblInput" runat="server" Text="Enter a String:"></asp:Label><br />
            <asp:TextBox ID="txtInput" runat="server" CssClass="form-control" placeholder="Example: madam"></asp:TextBox><br />

            <asp:Button ID="btnCheck" runat="server" Text="Check Palindrome" CssClass="btn" OnClick="btnCheck_Click" /><br />

            <asp:Label ID="lblResult" runat="server" CssClass="result"></asp:Label>
        </div>
    </form>
</body>
</html>

Step 2: Backend Logic – PalindromeString.aspx.cs

  
    using System;

public partial class PalindromeString : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void btnCheck_Click(object sender, EventArgs e)
    {
        string input = txtInput.Text.Trim().ToLower();

        if (string.IsNullOrEmpty(input))
        {
            lblResult.Text = "Please enter a valid string.";
            lblResult.ForeColor = System.Drawing.Color.Red;
            return;
        }

        if (IsPalindrome(input))
        {
            lblResult.Text = $" \"{input}\" is a Palindrome String.";
            lblResult.ForeColor = System.Drawing.Color.Green;
        }
        else
        {
            lblResult.Text = $" \"{input}\" is NOT a Palindrome String.";
            lblResult.ForeColor = System.Drawing.Color.Red;
        }
    }

    private bool IsPalindrome(string str)
    {
        int left = 0;
        int right = str.Length - 1;

        while (left < right)
        {
            if (str[left] != str[right])
                return false;

            left++;
            right--;
        }

        return true;
    }
}

Real-Time Example Flow

Open PalindromeString.aspx in your browser.
Enter a word (e.g., madam ).
Click “Check Palindrome” .
The output displays:

"madam" is a Palindrome String.
Try with another word (e.g., hello ):

"hello" is NOT a Palindrome String.

Explanation

Step	Description
1	Accept input string from user and convert it to lowercase.
2	Initialize two pointers: one from the start, one from the end.
3	Compare characters at both ends.
4	Move inward until all characters are checked.
5	If all pairs match → Palindrome; otherwise, not.

Sample Input / Output

Input	Output
madam	Palindrome
level	Palindrome
racecar	Palindrome
hello	Not Palindrome
apple	Not Palindrome