Re: Newbie Q: Zero fill in Put

[johnherro@aol.com (John Herro)]

Larry Coon <lmcoon@home.com> writes:
> How do I make [integers] output with
> leading zeros, eg: 02, 002, 00000002, etc?
> The width parameter seems to only fill with
> spaces.
     Here's one way to do it that works in Ada 83 as well as Ada 95.  Let
J be the integer and W be the width that you want.  I assume the integer is
non-negative and that it will fit in W spaces.  Add J to 10**W (here I
assume that this will not overflow).  Take the Integer'Image of the result,
which will always have a length of W+2 because of the leading space. 
Select the slice (3 .. W+2).
     For example, if J is 2 and you want a width of 3, this will print 002:
Ada.Text_IO.Put(Integer'Image(1000 + J)(3 .. 5));
     Obviously, this works with any integer type.  For example, many
compilers have Long_Integer.
     There are other ways to do what you want, but this way is quick and
simple if you know that J will never be large enough to cause an overflow. 
I hope this helps.
- John Herro
Software Innovations Technology
http://members.aol.com/AdaTutor
ftp://members.aol.com/AdaTutor