02(str) - 1(int)= 01(str)如何得到这样的结果？

Question

<?php

$str = "02";
$int = 1;

$result = $str-$int;

echo $result // 1

?>

但我需要result = 01

别告诉我 "0".$str-$int;

Answer 1

<?php
$str = "02";
$int = 1;

printf('%02d', $str-$int);

要么

<?php
$str = "02";
$int = 1;

$result = sprintf('%02d', $str-$int);
// do something with $result here

见http://docs.php.net/manual/en/function.sprintf.php