❗variable redeclaration

🚧 under construction

JS ⟩ variable ⟩ redeclaration

🚧 (redeclaration)

⭐️ 重點

(❗redeclaration ) JS is lenient with var, strict with let.

• var redeclaration applied even in strict mode❗️, even in strict mode❗

• let redeclaration not allowed even in sloppy mode❗️, even in sloppy mode❗

🔴 主題

• var redeclaration

  • var redeclaration applied even in strict mode❗️ (even in strict mode)❗

  • var can shadow parameter even in strict mode❗️ - parameters can be shadowed by "var"❗

• let redeclaration

  • let redeclaration not allowed even in sloppy mode❗️ (even in sloppy mode)❗

  • var can shadow parameter even in strict mode❗️ - parameters can't be shadowed by "let⛔

👥 相關

• variable declaration

• function redeclaration

• variable shadowing