💍value

a primitive or an object.

JS ⟩ value

a primitive or an object.

🔴 主題

• binding of values

  • static binding value of identifier is predetermined at compile-time.

  • dynamic binding value of identifier is not determined until runtime.

• getting values

  • RHS reference - get the value of a variable (if it exists).

• types of value

  • literal

    • object literal

    • template literal

  • primitive

    • Boolean / String / Number

    • Symbol / BigInt

    • undefined, null

  • object

    • built-in objects

      • Function - all kinds of functions.

    • type functions

      • isClass() - check if value is a class.

      • typeName() - value's type name.

⭐️ 重點

convert any value to Boolean.

!!x    // any -> true/false, same as Boolean(x)

convert any value to Number.

+x    // any -> number, same as `Number(x)`

👥 相關

• return statement will return a value to the function caller.

• typeof determines the type of a value. (👉 type name)

• argument is a value passed into function as input.

• null and undefined are the only two values that do not have property❗

📘 手冊

• Value