Q:

Seemingly unsupported unicode character in UILabel

I have a UILabel that displays a string coming in from a web service. It seems to be properly displaying some unicode characters, but not all. The string comes from the web service in a JSON object as follows:
"\u2b51 \u2605 Special Chars"
This is displayed in the UILabel like so:

Clearly, it's displaying the \u2605 character just fine but not the \u2b51 character. The font is Helvetica Neue--the system font.
Am I doing something wrong or is this a bug in iOS and/or the font?

A:

This seems to be purely a font issue. The character U+2605 BLACK STAR “★” is relatively common in fonts, so it is probably taken from a system font or a fallback font. The character U+2B51 BLACK SMALL STAR “⭑” is relatively rare; it was added in Unicode 5.1, i.e. rather recently (in the character code world, that is). According to Fileformat.info data, it appears in Code2000, FreeSerif, GNU Unifont, Quivira, STIX, STIXMath, and Symbola. Not much; most computers have none of them (though many Linux systems probably have FreeSerif). Well, it seems that you can add Asana Math and Universalia to the list; still rather limited.

