📜statement

JS ⟩ grammar ⟩ statement

JavaScript code consists of declarations and statements.

⭐️ 重點

⭐️ declarations and statements are different❗

👉 statement vs. declaration❗

statement vs. declaration

• 👉 var is a statement❗️ (not a declaration)

• let / const is declaration.

statement

• may have a label.

• If an expression corresponds to a sentence fragment, a statement corresponds to a full sentence.

• A program is a list of statements.

🔴 主題

• simple statements

  • expression

• control flow

  • return / break / continue / throw / yield / try-catch-finally

  • if / switch

• loops

  • while / do...while

  • for-of / for-in / for

• other statements

  • empty statement

  • block / label / debugger / with

  • import / export

• other topics

  • statements that must end with ";"

  • statement vs. declaration

  • statement expected❗️

📘 手冊

• MDN ⟩ JavaScript ⟩ Statements and declarations ⟩

  • block

  • return

  • let

📗 參考

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

• Eloquent JavaScript ⟩ Expressions & Statements

• Expressions versus statements in JavaScript ⭐️