03 — Arrays, Tuples & Enums

Core Concepts

• Typed Arrays — string[] or Array<string> syntax
• Readonly Arrays — readonly string[] or ReadonlyArray<string>
• Tuples — fixed-length arrays with specific types per position
• Labeled Tuples — tuples with named elements for readability
• Numeric Enums — auto-incrementing numeric values
• String Enums — explicit string values (preferred)
• const Enums — inlined at compile time, no runtime object
• Enum alternatives — as const objects (often preferred over enums)

Array vs Tuple

Enum Best Practices

• Prefer string enums over numeric (readable, debuggable)
• Consider as const objects instead of enums (tree-shakeable, no runtime overhead)
• Use const enum only if bundle size matters and you accept the trade-offs