Question

如何让它为1-9渲染前导0？

<?php foreach (range(1, 12) as $month): ?>


                  <option value="<?=$month?>"><?=$month?></option>

                <?php endforeach?>

Answer 1

<?php foreach (range(1, 12) as $month): ?>
  <option value="<?= sprintf("%02d", $month) ?>"><?= sprintf("%02d", $month) ?></option>
<?php endforeach?>

您可能希望将sprintf的值保存到变量中，以避免多次调用它。

Answer 2

使用str_pad()：

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

或sprintf()：

echo sprintf('%02d', $month);

Answer 3

$month = 1;
echo sprintf("%02d", $month);
out: 01

使用sprintf

Answer 4

array_map( function( $day ) {
    return str_pad( $day, 2, '0', STR_PAD_LEFT );
}, range(1, 31) );

结果：

Array
(
    [0] => 01
    [1] => 02
    [2] => 03
    [3] => 04
    [4] => 05
    [5] => 06
    [6] => 07
    [7] => 08
    [8] => 09
    [9] => 10
    [10] => 11
    [11] => 12
    [12] => 13
    [13] => 14
    [14] => 15
    [15] => 16
    [16] => 17
    [17] => 18
    [18] => 19
    [19] => 20
    [20] => 21
    [21] => 22
    [22] => 23
    [23] => 24
    [24] => 25
    [25] => 26
    [26] => 27
    [27] => 28
    [28] => 29
    [29] => 30
    [30] => 31
)

在PHP 5.3+中工作。自己尝试：https://3v4l.org/aE6HO

Answer 5

if($month < 10) echo '0' . $month;

或

if($month < 10) $month = '0' . $month;

PHP将前导0添加到范围

5 个答案: