📦expression

a statement that evaluates to a value.

JS ⟩ statement ⟩ expression

(statement) A fragment of code that produces a value.

🔴 主題

• operator

• primary expression

  • object literal / array literal

  • function expression

  • invocation expression：f() - calls a function.

• left-hand side expression

  • property access expression

⭐️ 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