⛔uninitialized variable

JS ⟩ variable ⟩ uninitialized variable

when a let / const / class is still in its temporal dead zone, it is said to be uninitialized.

⭐️ 重點

TDZ vs. uninitialized variable

• TDZ refers to the time window (time period) where a const/let variable exists but is still uninitialized (and cannot be accessed in any way).

• uninitialized variable refers to the const/let variable itself.

they are two sides of the same coin.

👥 相關

• uninitialized variable has no initial value, not undefined even❗

📗 參考

• YDKJS: Scope & Closures (v.2) ⟩

  • Ch. 1: What's the Scope? ⟩ Hoisting

  • Ch. 5 > Uninitialized Variables (aka, TDZ)

📘 手冊

• temporal dead zone