Interview Question

What is temporal dead zone?

Lexical bindings cannot be accessed before initialization.

💡 Concept ✅ Quick Revision ⚡ JavaScript

Answer

The temporal dead zone is the period when a lexical binding exists but is not initialized. • It begins when the scope is entered and ends when the declaration is evaluated. • Reading the binding during this period throws ReferenceError. • It applies to let, const, class, and other lexical declarations.

Example

Code

{
  // console.log(value); // ReferenceError
  const value = 5;
  console.log(value);
}

Output

Quick Revision

Lexical bindings cannot be accessed before initialization.

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