php - 具有某些值的数组中的意外行为

Question

我的代码是:

$arr=[02,05,07,08,09];
print_r($arr)

输出为:

Array
(
    [0] => 2
    [1] => 5
    [2] => 7
    [3] => 0
    [4] => 0
)

为什么将08和09转换为0？？

Answer 1

以零开头的数字被视为以 8 为基数。

请参阅 PHP 文档:Integers - Syntax .

To use octal notation, precede the number with a 0 (zero). To use hexadecimal notation precede the number with 0x. To use binary notation precede the number with 0b.