TypeScript for JavaScript Developers
12 lessons. Build on JavaScript with strict types, narrowing, generics, validated external data, and deterministic typed pipelines.
For learners who know variables, loops, functions, lists, and dictionaries. Written lessons, at your own pace.
All standard catalog courses are included in the course purchase.
01Inference and explicit boundariesDistinguish inferred local types from annotated function contracts.Free preview02Function signatures and missing resultsDescribe parameters, return values, and an explicit failure result.Free preview03Object types and optional propertiesModel records without losing valid falsy values.Course04Interfaces and readonly collectionsExpress reusable structures and avoid input mutation.Course05Unions and discriminated variantsNarrow a union before using variant-specific properties.Course06Unknown versus anyValidate unknown data before accessing it.Course07Generics that preserve relationshipsUse a type parameter to connect input and output types.Course08Typed Maps and SetsChoose collections with clear ordering and key semantics.Course09Utility types and safe projectionsUse Pick, Partial and Readonly without assuming runtime transformation.Course10Validating external dataConvert unknown input into a trusted result with runtime predicates.Course11Error results and recoverable failuresRepresent expected failure without confusing it with a valid value.Course12Typed pipelines and regression testsCompose validation, transformation and reporting with stable contracts.Course
Learn it. Then put it to work.
Pair the course with 32 challenges, progressive hints, and worked solutions.
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