📦left-hand side expression

🚧 under construction

JS ⟩ statement ⟩ expression ⟩ operator ⟩ left-hand side ⟩

(operator) ❓🚧

🔴 主題

• left-hand side expressions

  • property access expression ( ., [], ?., ?.[], ?.() )

  • new.target (in constructors) refers to the constructor itself.

  • new (object creation expression)

  • import.meta

    an object exposing context-specific metadata to a JavaScript module.

  • super calls the parent constructor.

  • ...obj

    spread syntax allows an expression to be expanded in places where multiple arguments (for function calls) or multiple elements (for array literals) are expected.

⭐️ 重點

two types of expressions

• those that have side effects (such as assigning values)

• those that purely evaluate.

you can use an expression to refer to an object's property.

👉 bracket notation []

📗 參考

• (2020) JavaScript The Definitive Guide, 1.3 A Tour of JavaScript

• JavaScript: The Definitive Guide ⟩

  • 1.3 A Tour of JavaScript

  • Ch. 4：Expressions & Operators

• Expressions versus statements in JavaScript ⭐️

• Javascript 的表達式 (Expressions) 和陳述式 (Statements)：一個用說的，一個用做的

📘 手冊

• Expressions and operators

❓問題

問：「為何 super, new, new.target, ... 這些稱為 left-hand side expression」❓

答：「...」