PHP

add leading zeros in php

$number = 4;
echo(str_pad($number, 2, '0', STR_PAD_LEFT)); // returns 04

$number = 14;
echo(str_pad($number, 2, '0', STR_PAD_LEFT)); // returns 14

php zeros before number php

$invID = str_pad($invID, 4, '0', STR_PAD_LEFT);