⛔'xxx' is not a function❗️

JS ⟩ error ⟩ TypeError ⟩ not a function❗

⛔️ TypeError：'xxx' is not a function❗

✨ 範例

• var hoisting

• function expression not hoisted

⭐️ 重點

calling a var (as function) before initialization will cause a

⛔ TypeError: 'xxx' is not a function

at runtime❗ 👉 var hoisting