PHP范围使用两位数代替一位

Question

i have the following code to create a select element of numbers from 0-99 using php range. I've tried to add the 00 to the range like this with no luck: range(00, 99) but it still just lists a single digit like 2 instead of 02. How do I alter this?

<select name="Vehic" id="Vehic" >
  <option value="">Truck</option>
  <?php 
        foreach (range(0, 99) as $trucknum) { ?>
  <option value="<?php echo($trucknum); ?>"><?php echo($trucknum); ?></option>
  <?php } ?>
</select>

Answer 1

在输出上。

<? printf('%02d', $trucknum); ?>

Answer 2

Use str_pad() :

echo str_pad($trucknum, 2, '0',  STR_PAD_LEFT);

In your code:

<select name="Vehic" id="Vehic" >
  <option value="">Truck</option>
  <?php 
        foreach (range(0, 99) as $trucknum) { ?>
          <?php
            $trucknumStr = str_pad($trucknum, 2, '0',  STR_PAD_LEFT);
          ?>
          <option value="<?php echo($trucknum); ?>"><?php echo($trucknumStr); ?></option>
  <?php } ?>
</select>

Answer 3

$trucknum is a numeric value, you will have to format the output to add leading zeroes when needed. See http://php.net/manual/en/function.printf.php

Answer 4

this worked <?php echo sprintf('%02d', $i); ?> <?php echo sprintf('%02d', $i); ?>