CSS:after encoding characters in content - css

Question

I am using the following CSS, which seems to be working:
a.up:after{content: " ↓";}
a.down:after{content: " ↑";}
The characters however cannot seem to be encoded like this, as the output is literal and shows the actual string:
a.up:after{content: " ↓";}
a.down:after{content: " ↑";}
If I can't encode it, it feels like I should use something such as .append() in jQuery, as that supports the encoding. Any ideas?

Answer 1

To use encoded Unicode characters in content you need to provide either the characters themselves (as you do), or their UTF-8 escape sequences instead of HTML entities:
a.up:after { content: " \2193"; }
a.down:after { content: " \2191"; }

Answer 2

Why do you want to encode those characters anyway? Remember, you're writing CSS, not HTML. Your code:
a.up:after{content: " ↓";}
a.down:after{content: " ↑";}
is perfectly valid, as long as you save the file with UTF-8 encoding and send the appropriate header:
Content-Type: text/css; charset=utf-8
Encoding characters is only used in HTML so that there is no ambiguity between content and tags. Thus, you would encode< as < so that the browser doesn't think it's the beginning of a tag. Stuff like ↓ are just commodities for people who don't know how to use utf-8 (or can't, for whatever reason) :).

Answer 3

Just want to add that if you want to set dynamically the value of content via the attr() function, the above won't work. See
document.getElementById('wontwork').setAttribute('data-sym', ' \2714 ');
document.getElementById('willwork').setAttribute('data-sym', ' \u2714 ');
button::before {
content: attr(data-sym);
}
* {
font-size: 30px
}
<button id='wontwork' data-sym='to-be-replaced'>not rendered</button>
<button id='willwork' data-sym='to-be-replaced'>rendered !</button>