how to enter certain numbers in Textboxes

Question

Initial numbers should enter certain numbers: Like: TextBox1: 111152022232020 TextBox2: 222202350142500 TextBox3: 3333012001200123 INTIAL NO. 1111 2222 33333 PLS HELP ME

Rajeesh Menoth · Answer

Hi Do you want to check each textbox separately then you need to check the following code logic. using System; public class Program { public static void Main() { string TextBox1 = 111152022232020 ; string TextBox2 = 222202350142500 ; string TextBox3 = 3333012001200123 ; if (TextBox1.StartsWith( 1111 )) Console.WriteLine( hai ); else Console.WriteLine( Not Contain Intial Numbers ); if (TextBox2.StartsWith( 2222 )) Console.WriteLine( hai ); else Console.WriteLine( Not Contain Intial Numbers ); if (TextBox3.StartsWith( 3333 )) Console.WriteLine( hai ); else Console.WriteLine( Not Contain Intial Numbers ); } } Demo : https://dotnetfiddle.net/Dc2z5s

Dhananjay Kumar · Answer

if (TextBox1.Text.StartsWith(1234) || TextBox1.Text.StartsWith(7811) || TextBox1.Text.StartsWith(8524) || TextBox1.Text.StartsWith(4511)) { // then proceed with the functions } else { // return Invalid number... }