str_pad

PHP has a very useful function called str_pad(). It allows you to ensure that a string will conform to a specific length by adding characters of your choice on the end of your choice. A good practical example is when you want a number with leading zeros. ASP doesn't have an equivalent function out of the box, but we're going to write one today; as usual, we'll follow the same syntax to make it easy for those who are already familiar with PHP.

ASP

1. Const STR_PAD_LEFT = "LEFT"
2. Const STR_PAD_RIGHT = "RIGHT"
3. Const STR_PAD_BOTH = "BOTH"
5. ' Pad a string to a certain length with another string.
6. function str_pad(input, pad_length, pad_string, pad_type)
7.     dim output
8.     dim difference
10.     output = ""
11.     difference = pad_length - len(input)
13.     if difference > 0 then
14.         select case ucase(pad_type)
15.         case "LEFT"
16.             for i = 1 to difference step len(pad_string)
17.                 output = output & pad_string
18.             next
20.             output = right(output & input, pad_length)
21.         case "BOTH"
22.             output = input
24.             for i = 1 to difference step len(pad_string) * 2
25.                 output = pad_string & output & pad_string
26.             next
28.             ' Not sure if it will step far enough when difference is an odd number, so this next block is just in case.
29.             if len(output) < pad_length then
30.                 output = output & pad_string
31.             end if
33.             output = left(output, pad_length)
34.         case else
35.             for i = 1 to difference step len(pad_string)
36.                 output = output & pad_string
37.             next
39.             output = left(input & output, pad_length)
40.         end select
41.     else
42.         output = input
43.     end if
45.     str_pad = output
46. end function

Thinking back to my days as a web developer, this was probably the most reused function out of all I'd ever written.

View ASP implementation on Snipplr