为什么 HTML 认为“chucknorris"是一种颜色? [英] Why does HTML think “chucknorris” is a color?
问题描述
为什么某些随机字符串在 HTML 中作为背景颜色输入时会产生颜色?
Why do certain random strings produce colors when entered as background colors in HTML?
例如:
<body bgcolor="chucknorris"> test </body>...在所有浏览器和平台上生成具有红色背景的文档.
...produces a document with a red background across all browsers and platforms.
另一方面，chucknorr 产生黄色背景！
这是怎么回事?
推荐答案
这是 Netscape 时代的产物:
It’s a holdover from the Netscape days:
缺失的数字被视为 0[...].错误的数字被简单地解释为 0.例如，#F0F0F0、F0F0F0、F0F0F、#FxFxFx 和 FxFxFx 的值都是相同的.
Missing digits are treated as 0[...]. An incorrect digit is simply interpreted as 0. For example the values #F0F0F0, F0F0F0, F0F0F, #FxFxFx and FxFxFx are all the same.
它来自博客文章对 Microsoft Internet Explorer 的颜色解析的一点抱怨，其中详细介绍了它，包括不同长度的颜色值等.
It is from the blog post A little rant about Microsoft Internet Explorer's color parsing which covers it in great detail, including varying lengths of color values, etc.
如果我们依次应用博文中的规则，我们会得到以下结果:
If we apply the rules in turn from the blog post, we get the following:
将所有无效的十六进制字符替换为 0:
Replace all nonvalid hexadecimal characters with 0’s:
chucknorris becomes c00c0000000
填充到下一个可被 3 整除的字符总数 (11 → 12):
Pad out to the next total number of characters divisible by 3 (11 → 12):
c00c 0000 0000
分成三个相等的组，每个分量代表 RGB 颜色的相应颜色分量:
Split into three equal groups, with each component representing the corresponding colour component of an RGB colour:
RGB (c00c, 0000, 0000)
将每个参数从右边截断为两个字符.
Truncate each of the arguments from the right down to two characters.
最后得到以下结果:
RGB (c0, 00, 00) = #C00000 or RGB(192, 0, 0)
这是一个示例，演示了 bgcolor 属性的作用，以产生这个惊人"的颜色样本:
Here’s an example demonstrating the bgcolor attribute in action, to produce this "amazing" colour swatch:
<table>
<tr>
<td bgcolor="chucknorris" cellpadding="8" width="100" align="center">chuck norris</td>
<td bgcolor="mrt" cellpadding="8" width="100" align="center" style="color:#ffffff">Mr T</td>
<td bgcolor="ninjaturtle" cellpadding="8" width="100" align="center" style="color:#ffffff">ninjaturtle</td>
</tr>
<tr>
<td bgcolor="sick" cellpadding="8" width="100" align="center">sick</td>
<td bgcolor="crap" cellpadding="8" width="100" align="center">crap</td>
<td bgcolor="grass" cellpadding="8" width="100" align="center">grass</td>
</tr>
</table>这也回答了问题的另一部分:为什么 bgcolor="chucknorr" 会产生黄色?好吧，如果我们应用规则，字符串是:
This also answers the other part of the question: Why does bgcolor="chucknorr" produce a yellow colour? Well, if we apply the rules, the string is:
c00c00000 => c00 c00 000 => c0 c0 00 [RGB(192, 192, 0)]
呈现淡黄色金色.由于字符串以 9 个字符开头，因此这次我们保留第二个C"，因此它以最终颜色值结束.
Which gives a light yellow gold colour. As the string starts off as 9 characters, we keep the second ‘C’ this time around, hence it ends up in the final colour value.
当有人指出您可以执行 color="crap" 时，我最初遇到了这个问题，但结果是棕色的.
I originally encountered this when someone pointed out that you could do color="crap" and, well, it comes out brown.
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