Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

String

Growable text the program owns.

String is an owned, growable, heap-allocated, always-valid UTF-8 text buffer.

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Examples

let mut message = String::from("Hello"); message.push_str(", world"); grows the text to Hello, world.