PHP add thousand separators to number and keep leading zeros - php

Question

I'm trying to add thousand separators to a number using PHP and at the same time keep the leading zeros (It's part of the design of an app that the leading 0s stay so that people can see the number grow towards the set target - a 6 figure number).
My initial attempt was to use str_pad to add the leading zeros if the current number calculated was less than 6 figures long. Then to add the commas I used number_format. The obvious issue is that number_format removes the leading 0s.
$num = 550;
$num_padded = str_pad($num, 6, '0', STR_PAD_LEFT);
echo number_format($num_padded);
So that returns 550 instead of 000,550
Does anyone know of a reliable way to achieve the format I'm looking for?
Thanks!

Answer 1

I have in mind this simple trick:
function padAndFormat($number, $length)
{
if(strlen($number)>=$length)
{
return number_format($number);
}
$number = number_format('1'.str_pad($number, $length-1, '0', STR_PAD_LEFT));
$number[0] = '0';
return $number;
}
//var_dump(padAndFormat('517', 6)); //string(7) "000,517"

Answer 2

another way to do this is to use sprintf
// length can be changed, here is 6
implode(',',str_split(sprintf('%06d', $this->iterator),3));
the result will be :
input
result
4
000,004
400
000,400
23560
023,560
1234567
1,234,567
it can be improved by reading the length, and computing automatically the final length, multiple of 3

Answer 3

I don't need number format but I need that comma! :)
<?php
$zeroes=0;
$num = 550;
$num_padded = str_pad($zeroes, 3, '0', STR_PAD_LEFT);
$num_padded = str_pad($num_padded,strlen($num_padded)+strlen($zeroes), ',', STR_PAD_RIGHT);
$num_padded = str_pad($num_padded,strlen($num_padded)+strlen($num), $num, STR_PAD_RIGHT);
echo $num_padded;
OUTPUT :
000,550

Answer 4

One Liner with PHP string manipulation. Works for any number of digits:
function pad($number, $min_digits){
return strrev(implode(",",str_split(str_pad(strrev($number), $min_digits, "0", STR_PAD_RIGHT),3)));
}
/* Output for 9 digits
0,000,001
0,000,012
0,000,123
0,001,234
0,012,345
0,123,456
1,234,567
12,345,678
123,456,789
/**/