Whats the cleanest way to convert a 5-7 digit number into xxx/xxx/xxx format in php?

Question

I have sets of 5, 6 and 7 digit numbers. I need them to be displayed in the 000/000/000 format. So for example:

12345 would be displayed as 000/012/345

and

9876543 would be displayed as 009/876/543

I know how to do this in a messy way, involving a series of if/else statements, and strlen functions, but there has to be a cleaner way involving regex that Im not seeing.

Answer 1

sprintf and modulo is one option

function formatMyNumber($num)
{
    return sprintf('%03d/%03d/%03d',
                   $num / 1000000,
                  ($num / 1000) % 1000,
                   $num % 1000);
}

Answer 2

Here's how I'd do it in python (sorry I don't know PHP as well). I'm sure you can convert it.

def convert(num): #num is an integer
    a = str(num)
    s = "0"*(9-len(a)) + a
    return "%s/%s/%s" % (s[:3], s[3:6], s[6:9])

This just pads the number to have length 9, then splits the substrings. That being said, it seems the modulo answer is a bit better.

Answer 3

$padded = str_pad($number, 9, '0', STR_PAD_LEFT);
$split = str_split($padded, 3);
$formatted = implode('/', $split);

Answer 4

OK, people are throwing stuff out, so I will too!

number_format would be great, because it accepts a thousands separator, but it doesn't do padding zeroes like sprintf and the like. So here's what I came up with for a one-liner:

function fmt($x) {
    return substr(number_format($x+1000000000, 0, ".", "/"), 2);
}

Answer 5

You asked for a regex solution, and I love playing with them, so here is a regex solution!
I show it for educational (and fun) purpose only, just use Adam's solution, clean, readable and fast.

function FormatWithSlashes($number)
{
    return substr(preg_replace('/(\d{3})?(\d{3})?(\d{3})$/', '$1/$2/$3',
            '0000' . $number),
            -11, 11);
}

$numbers = Array(12345, 345678, 9876543);
foreach ($numbers as $val)
{
    $r = FormatWithSlashes($val);
    echo "<p>$r</p>";
}

Answer 6

Minor improvement to PhiLho's suggestion:

You can avoid the substr by changing the regex to:

function FormatWithSlashes($number)
{
    return preg_replace('/^0*(\d{3})(\d{3})(\d{3})$/', '$1/$2/$3',
            '0000' . $number);
}

I also removed the ? after each of the first two capture groups because, when given a 5, 6, or 7 digit number (as specified in the question), this will always have at least 9 digits to work with. If you want to guard against the possibility of receiving a smaller input number, run the regex against '000000000' . $number instead.

Alternately, you could use

substr('0000' . $number, -9, 9);

and then splice the slashes in at the appropriate places with substr_replace, which I suspect may be the fastest way to do this (no need to run regexes or do division), but that's really just getting into pointless optimization, as any of the solutions presented will still be much faster than establishing a network connection to the server.

Answer 7

This would be how I would write it if using Perl 5.10 .

use 5.010;

sub myformat(_;$){

  # prepend with zeros
  my $_ = 0 x ( 9-length($_[0]) ) . $_[0];

  my $join = $_[1] // '/'; # using the 'defined or' operator `//`

  # m// in a list context returns ($1,$2,$3,...)
  join $join, m/ ^ (\d{3}) (\d{3}) (\d{3}) $ /x;

}

Tested with:

$_ = 11111;
say myformat;
say myformat(2222);
say myformat(33333,';');
say $_;

returns:

000/011/111
000/002/222
000;033;333
11111

Back-ported to Perl 5.8 :

sub myformat(;$$){
  local $_ = @_ ? $_[0] : $_

  # prepend with zeros
  $_ = 0 x ( 9-length($_) ) . $_;

  my $join = defined($_[1]) ? $_[1] :'/';

  # m// in a list context returns ($1,$2,$3,...)
  join $join, m/ ^ (\d{3}) (\d{3}) (\d{3}) $ /x;

}