Hoisting in JavaScript

What is Hoisting in JavaScript?

Hoisting is the behavior of moving declarations to the top of their scope before the code is executed.

Hoisting with var:

Variables declared with var are hoisted and initialized with undefined.

Example:

<script>
console.log(name);

var name = "Raksha";

</script>

Output:

undefined

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Hoisting with let:

• Variables declared with let are hoisted but not initialized.
• They remain in the Temporal Dead Zone (TDZ) until the declaration is reached.

What is Temporal Dead Zone?

• TDZ (Temporal Dead Zone) is the period between entering a scope and the point where a let or const variable is declared and initialized.
• During this period, the variable exists in memory, but JavaScript does not allow access to it.

Example:

<script>
console.log(age);

let age = 21;
</script>

Output:

ReferenceError: Cannot access 'age' before initialization.

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Hoisting with const:

• Variables declared with const are hoisted but not initialized.
• They remain in the Temporal Dead Zone (TDZ) until the declaration is reached.
• const behaves similarly to let.

Example:

<script>
console.log(PI);

const PI = 3.14;
</script>

Output:

ReferenceError: Cannot access 'age' before initialization.

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