Learn a Language by Comparison

Fill these in and the prompt below updates as you type. Anything you leave blank stays as a placeholder.

I'm an experienced {{known_language}} developer learning {{new_language}}.

Teach me {{new_language}} by comparison: for each core concept (variables, functions, control flow, data structures, error handling, async, types, modules), show the {{known_language}} way I already know, then the {{new_language}} equivalent with idiomatic patterns.

Highlight the "gotchas" — things that look the same but behave differently.

What are the biggest mindset shifts I need to make? What {{known_language}} habits will hurt me in {{new_language}}?

Give me a learning roadmap: what to learn in what order for a developer at my level.