当我在RegEx中转义<字符时，为什么jslint会抱怨？

Question

The code: var foo = /\\</;

When I go to jslint.com and enter that in, I get:

Problem at line 1 character 12: Unexpected '\\'.

It used to tell me Unexpected escaped character '<' in regular expression. but times have changed.

So I'm just curious, why? If you try var foo = /\\>/; it doesn't care, what's the deal with < ?

Answer 1

If you have a two simple divs, the difference is clear:

<div> < </div> <!--Missing right angle bracket, bad markup-->
<div> > </div> <!--No problem, just a greater than text node-->

JSLint does not assume that the script is a standalone file or inside a script tag of an HTML document. In markup languages such as XUL , MXML , XAML , TVML , LZX , XHTML5 or SVG , the script tag content is treated like the first div in the above example, so the left angle bracket will look like the start of a tag. In those languages, use an entity replacement or a CDATA block to wrap the left angle bracket and ampersand characters:

<script> 
if ( -1 &lt; 0 &amp;&amp; true !== false) {} 
</script>

<script>
<![CDATA[
if ( -2 < 0 && true !== false) {}
]]>
</script>

References

• Escaped Markup Considered Harmful