php plus number keep zero as first character-CodePudding

I have this code:

$i = '0001';
$j = $i   1;

I want to get 0002 but it give me only 2 How can I plus $i and keep that 000?

Thank you

CodePudding user response：

PHP took a useful feature from Perl: the ability to increment strings, using . Unfortunately, it didn't do it very well. If you increment "A0001", you get "A0002"; but if you increment "0001", you get 2 (as opposed to original Perl, which would give you "0002"). But, you can cheat:

$i="0001";
$j=":$a";
$j  ;
$j=substr($j, 1);

This is more to both illustrate a cool thing not many people might be aware of, and how it was misimplemented, than to provide a real solution; I would definitely prefer to see a str_pad or sprintf solution in my code.

CodePudding user response：

You can use str_pad to keep the leading zeroes.

Code here,

<?php
$i = '0001';
$val = $i   1;
echo str_pad($val,4,"0",STR_PAD_LEFT); // 0001
?>

Click to learn more about str_pad

CodePudding user response：

Maybe this can give you an idea:

$i = '0001';
$i = intval($i);
$i  ;
$a = '000';
$result = $a.$i;
echo $result;

The . between $a and $i is concatenating the variables into a string, keeping every character in them. The code above will output 0002 Check it here: http://sandbox.onlinephpfunctions.com/code/fc2bd5861a6c0d937568b067e98e06977741019c

If you want to keep all leading zeroes, you could count them separately and increment it like this. Of course, this is something whipped out quickly and I'm 100% certain there are much better ways of doing this out there.