php 数组行为奇怪，键值 07 &08 [英] php array behaving strangely with key value 07 & 08

问题描述

我有几个月的数组

$months[01] = 'January';
$months[02] = 'February';
$months[03] = 'March';
$months[04] = 'April';
$months[05] = 'May';
$months[06] = 'June';
$months[07] = 'July';
$months[08] = 'August';
$months[09] = 'September';
$months[10] = 'October';
$months[11] = 'November';
$months[12] = 'December';

现在数组没有为键 07 输出正确的值 &08.

Now the array does not output correct value for key 07 & 08.

尝试执行 print_r($months) 你不会得到任何键值 August 和 September 的零键索引.

Try doing print_r($months) you will not get any key value August and zero key index for September.

虽然我可以通过删除前导零来解决问题，但我仍然很想知道相同的原因.

Though I’m able to solve the problem by removing the leading zero, still I would love to know the reason for same.

即使是 PHP 编辑器也发现了一些问题，但无法说出问题所在.

Even the PHP editor spots some problem but unable to tell what is the problem.

谢谢

推荐答案

在数字前添加 0 意味着 PHP 将其解析为八进制值，就像添加 0x 导致它被解析为十六进制值一样.删除零，它会正常工作.

Prepending 0 before a number means PHP parses it as an octal value in the same way that prepending 0x causes it to be parsed as a hexadecimal value. Remove the zero, and it will work fine.

echo 07; // prints 7
echo 010; // prints 8

这主要用于指定 unix 权限时:

This is mostly used when specifying unix permissions:

chmod("myfile", 0660);

除此之外，您很少会想做.

Except for that it's rarely something that you'd want to do.

这在 PHP 手册中有所描述.

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