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Type Annotation ↔ TS Syntax to annotate Variables with Types

Angle Bracket Notation​

<\> Type Expression to define Generic Type Placeholder

Type Annotation provide Syntactic Sugar for checking Types of objects at Compile Time

built-in JS functions (ie JSON.parse()) return any by default - always will need manual Type Annotation

References​

  1. Type Inference ↔ (feature) TSC to auto-derive implicit Type for Variable (w/o explicit Type Annotation)

  2. Alias ↔ custom Type to store & reuse Type Annotation & improve Readability

  3. Object Literal Type ↔ Type Annotation for Object Literal, use for inline anon Object pass as arg

  4. Object Optional Property ↔ ?: Type Annotation to mark optional object property

  5. Function Signature ↔ Type Annotation to define function I/O

  6. Variadic Tuple ↔ Tuple Type Annotation using Spread Operator or Rest Parameter, to define varying number of element types

  7. Typed Callback Function ↔ Type Annotation for Anon Function pass as arg to function