Day 5 of 14 30 minUnionsLiteral typesDiscriminated unions
Model values that can be one of several types. Write unions of types and of literal values, see what you can do with a union before checking it, and model different kinds of data with discriminated unions.
By the end of today you can
- Write union types with the | operator
- Use literal unions to allow only specific values
- Explain which operations are allowed on a union before narrowing
- Model alternatives with discriminated unions
- Replace bags of optional properties with clearer unions
What's inside
- 4 sections
- 2 diagrams and mind maps
- 6 code examples you can run
- 5-question quiz
- 1Unions of types
- 2Literal unions: an exact list of values
- 3Discriminated unions
- 4Modelling: make impossible states impossible
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