How to display the number “12” in the format of “0000012”

Question

How to display the number “12” in the format of “0000012” Using C#

Answer 1

var str = string.Format("{0:d7}", 12);

Answer 2

var formatted = String.Format("{0:0000000}", 12);

or

Console.WriteLine("{0:0000000}", 12);

I will add that if "12" is a string (it's in double quotes)

var formatted = "12".PadLeft(7, '0');