How to add Leading Zeroes to a Number (Delphi Format)

Here‘s how convert (an integer) number to a string by adding an amount of leading zeroes.

Suppose you are developing a database application, and you need to operate on, let‘s say, a customer number, where each number needs to be exactly 10 digits "long" - but you have customer numbers of 2,4,7, etc. (<10) digits.

The AddLeadingZeroes function accepts two parameters: aNumber is the number that needs to have exactly Length characters (if less, add leading zeroes).

function AddLeadingZeroes(const aNumber, Length : integer) : string;
begin
   result := SysUtils.Format(‘%.*d‘, [Length, aNumber]) ;
end;

Usage:

AddLeadingZeroes(2005, 10) ;

Will result in a ‘0000002005‘ string value.