What is difference between OR (|) and Logical OR (||) ?

1. Logical OR Sign is || and AND Sign is  |.

2. Both work is same but Operation Method is Different 

for example 

if(a==10 || b==10) 

here if a =10 then condition is Satisfied and not going checking values of B. 

Moral One Operation for checking second i.e B values decrasesand in AND & operation 

if(a==10 | b==10)

here if a ==10 then also it is checking B value i.e  it is not necessary.    
    
Logical OR(||) is Best.    

What is difference between AND & and Logical AND &&?

1. Logical AND Sign is && and AND Sign is  &.

2. Both work is same but Operation Method is Different

for example

if(a==10 && b==10)

here if a =10 then only it going for  checking b value

if a !=10 then condition is not satisfied.

Moral One Operation for checking second values decrases

and in AND & operation

if(a==10 & b==10)

here if a !=10 then also it is checking B value it is not necessary.

Logical AND(&&) is Best.    

Custom Validation On ServerSide For Validate Number in asp.net

Server Side Custom Validation  For Number. 

it is check regular expression for Number and must be not  null value means 

Required Field Validation.

 CustomValidation.aspx 

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>CustomValidation ASPdotNet-Example.blogspot.com</title>
</head>
<body>
    <form id="form1" runat="server">
    <center>
    <h1>
        CustomValidation ASPdotNet-Example.blogspot.com</h1>
    <div>
        <table>
            <tr>
                <td>
                &nbsp;
                </td>
                <td>
  <asp:CustomValidator ID="CustomValidatorNumber" runat="server" ForeColor="Red" 
  ControlToValidate="txtValidation" ValidationGroup="Number"
  onservervalidate="CustomValidatorNumber_ServerValidate" 
                        ValidateEmptyText="True"></asp:CustomValidator>
                </td>
            </tr>
            <tr>
                <td>
  <asp:Label ID="lblNumber" runat="server"  Text="Number"></asp:Label>
                </td>
                <td>
 <asp:TextBox ID="txtValidation" ValidationGroup="Number" runat="server">

</asp:TextBox>
                </td>
            </tr>
            <tr>
                <td>
                &nbsp;
                </td>
                <td>
  <asp:Button ID="btnSubmit" runat="server" Text="Submit" ValidationGroup="Number"
      onclick="btnSubmit_Click" />
                </td>
            </tr>
            <td>
                &nbsp;
                </td>
                <td>
         <asp:Label ID="lblMsg" runat="server" ForeColor="Green"></asp:Label>
                </td>
        </table>
    </div>
    </center>
    </form>
</body>
</html>

CustomValidation.aspx.cs