Csharp/CSharp Tutorial/Data Type/Integer format

Use ToString() to format integers

using System; 
 
class MainClass { 
  public static void Main() { 
    int x = 21; 
    string str = x.ToString("X"); 
    Console.WriteLine(str); 
 
    str = x.ToString("D12"); 
    Console.WriteLine(str); 
 
  } 
}

15
000000000021