What is the Temporal Dead Zone and How Does it Affect `let` and `const` Variables?

Temporal Dead Zone and its Effect on 'let' and 'const' Declarations

The temporal dead zone refers to a period of time during which a variable declared with 'let' or 'const' is inaccessible within a block or scope. This occurs before its declaration and initialization within the scope.

Scope and Hoisting

'let' and 'const' have block scope, unlike 'var' which has function scope. Hoisting, a JavaScript phenomenon, raises variable declarations to the top of their enclosing scope. However, for 'let' and 'const', only the declarations are hoisted, not the assignments.

Encountering the Temporal Dead Zone

The temporal dead zone is encountered when:

• Accessing a 'let' or 'const' variable before its declaration in a block:

console.log(aLet); // Throws ReferenceError

• Attempting to access a 'let' or 'const' variable before its initialization within a block:

let aLet;  // Declaration
console.log(aLet); // undefined (let can be declared without initialization)

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