Question

Being a application developer, do I need to know Unicode?

Answer 1

Unicode is a standard that defines numeric codes for glyphs used in written communication. Or, as they say it themselves:

The standard for digital representation of the characters used in writing all of the world’s languages. Unicode provides a uniform means for storing, searching, and interchanging text in any language. It is used by all modern computers and is the foundation for processing text on the Internet. Unicode is developed and maintained by the Unicode Consortium.

There are many common, yet easily avoided, programming errors committed by developers who don’t bother to educate themselves about Unicode and its encodings.

• First, go to the source for authoritative, detailed information and implementation guidelines.
• As mentioned by others, Joel Spolsky has a good list of these errors.
• I also like Elliotte Rusty Harold’s Ten Commandments of Unicode.
• Developers should also watch out for canonical representation attacks.

Some of the key concepts you should be aware of are:

• Glyphs—concrete graphics used to represent written characters.
• Composition—combining glyphs to create another glyph.
• Encoding—converting Unicode points to a stream of bytes.
• Collation—locale-sensitive comparison of Unicode strings.