🦠primitive

🚧 under construction

JS ⟩ value ⟩ primitive

7 primitive data types:

• 5 with wrapper： String / Number / BigInt / Boolean / Symbol

• 2 without wrapper：(⚠️ can't call methods, no properties)❗ undefined / null.

🔴 主題

• 7 types of primitives

  • null / undefined

  • Boolean / Number / String

  • BigInt / Symbol

• tools

  • isPrimitive() / isObject()

⭐️ 重點

All primitives are immutable.

null & undefined

• have no object wrappers, methods/properties not available.

• hava no corresponding prototype either.

👥 相關

• 👉 isPrimitive()

• ⭐ sloppy equality (==) / strict equality (===)

📗 參考

• JS.info ⟩ Native prototypes ⟩ primitives

📘 手冊

• Primitive

🚧

• Symbol's wrapper?