What is hoisting in JavaScript with let and const?

What is hoisting in JavaScript with let and const?

Hoisting is a JavaScript mechanism where variables and function declarations are moved to the top of their containing scope during compilation. However, with let and const, the variables are hoisted but not initialized, leading to a 'Temporal Dead Zone'.

Can you explain the Temporal Dead Zone?

The Temporal Dead Zone (TDZ) refers to the time span within the block where a variable is in scope but not yet initialized. Accessing it before declaration results in a ReferenceError.

What happens if I try to access a let variable before it's declared?

If you try to access a let variable before its declaration, you'll get a ReferenceError due to the TDZ. This is different from var, which would return undefined.

Are there any practical examples of hoisting with let and const?

Yes! For example, if you declare a let variable inside a function and try to log it before the declaration, you'll see a ReferenceError. This behavior helps prevent bugs that can occur with variable declarations.