How to format integer as string with 2 digits?

Question

I would like to format an integer 9 to "09" and 25 to "25".

How can this be done?

Answer 1

You can use either of these options:

The "0" Custom Specifier

• value.ToString("00")
• String.Format("{0:00}", value)

The Decimal ("D") Standard Format Specifier

• value.ToString("D2")
• String.Format("{0:D2}", value)

For more information:

• Custom Numeric Format Strings
• Standard Numeric Format Strings

Answer 2

If its just leading zero's that you want, you can use this:

value.tostring.padleft("0",2)
value.ToString().PadLeft(2, '0');   // C#

If you have 2 digits, say 25 for example, you will get "25" back....if you have just one digit, say 9 for example, you will get "09"....It is worth noting that this gives you a string back, and not an integer, so you may need to cast this later on in your code.

Answer 3

String formate is the best way to do that. It's will only add leading zero for a single length. 9 to "09" and 25 to "25".

String.format("%02d", value)

Bonus: If you want to add multiple leading zero 9 to "0009" and 1000 to "1000". That's means you want a string for 4 indexes so the condition will be %04d.

String.format("%04d", value)

Answer 4

I don't know the exact syntax. But in any language, it would look like this.

a = 9
aString =""

if a < 10 then 
  aString="0" + a 
else 
  aString = "" + a
end if