带有前导零的PHP二进制到十六进制 [英] PHP Binary to Hex with leading zeros

问题描述

我有以下代码：

I have the follow code:

<?
$binary = "110000000000";
$hex = dechex(bindec($binary));
echo $hex;
?>

哪些工作正常，我得到c00的值。

Which works fine, and I get a value of c00.

然而，当我尝试转换000000010000时，我得到值10。我真正想要的是所有的前导零，所以我可以得到010作为最终结果。

However, when I try to convert 000000010000 I get the value "10". What I actually want are all the leading zeros, so I can get "010" as the final result.

我该怎么做？

编辑：我应该指出，二进制数的长度可能会有所不同。所以$ binary可能是00001000，这会导致它为08。

I should point out, the length of the binary number can vary. So $binary might be 00001000 which would result it 08.

推荐答案

您可以在前面加上必要数量的前导零， ：

You can prepend the requisite number of leading zeroes with something such as:

$hex = str_repeat("0", floor(strspn($binary, "0") / 4)).$hex;

这是干什么的？

What does this do?

1. 它发现你的二进制字符串有多少个前导零，它们是 strspn 。


2. 它将它转换为数字你需要十六进制表示的前导零。整组的4个前导零位需要转换为一个零十六进制数字;任何剩余的零位已经被编码在输出的第一个非零十六进制数字中，所以我们使用 floor 将它们排除。


3. 它使用 str_repeat 。

1. It finds out how many leading zeroes your binary string has with strspn.
2. It translates this to the number of leading zeroes you need on the hex representation. Whole groups of 4 leading zero bits need to be translated to one zero hex digit; any leftover zero bits are already encoded in the first nonzero hex digit of the output, so we use floor to cast them out.
3. It prepends that many zeroes to the result using str_repeat.

注意，如果结果为零输入位的数量不是4的倍数，这可能导致一个比预期的零十六进制数字更少。如果这是可能的，您需要相应调整。

Note that if the number of input bits is not a multiple of 4 this might result in one less zero hex digit than expected. If that is a possibility you will need to adjust accordingly.

这篇关于带有前导零的PHP二进制到十六进制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！