Writing about text

Where to start

If you work with text in bulk, read the mistakes find-and-replace makes first. It is the one piece here that prevents damage rather than explaining it, and the failure it describes is quiet: a replacement that worked on every line you checked and corrupted three you did not.

After that, invisible characters in text covers the other common source of unexplained behaviour, where a string that looks identical to another one is not, and nothing on screen tells you why.

What these pieces have in common

Text looks simple because reading it is effortless, and that is the trap. What a computer stores is a sequence of codepoints, and nearly every surprise in this category comes from the gap between the two. A space may be one of several different characters. A letter with an accent may be one codepoint or two. Two strings that print identically can fail an equality check.

The writing here is mostly about closing that gap for cases that come up often: what title case actually is and why no two style guides agree, the naming conventions and where each belongs, what sorting really does, and what makes a URL slug readable to a person and durable to a search engine.

Frequently asked questions

What is an invisible character and how does one get into my text?

Zero-width spaces, non-breaking spaces, soft hyphens and direction marks all occupy a position in a string without drawing anything. They arrive through copy and paste from word processors, PDFs and web pages, and they break exact matches, URL parsing and code while looking completely normal on screen.

Is there one correct way to write title case?

No. AP, Chicago and APA each have their own rule about which short words stay lowercase, and they disagree with each other. Every automatic title case converter has silently picked one of them. For anything published, the right answer is whichever style guide the publication already follows.

When should I use camelCase, snake_case or kebab-case?

It is almost entirely convention rather than merit, and the convention belongs to the context. JavaScript and Java use camelCase for variables, Python and SQL use snake_case, and kebab-case belongs in URLs and CSS class names, where an underscore is harder to see in an underlined link.