The Temporal Dead Zone (TDZ) only applies to variables declared with <code>let</code> and <code>const</code> keywords in JavaScript, and not to variables declared with <code>var</code>.
In JavaScript, variables declared with <code>var</code> are hoisted to the top of their respective scopes and are initialized with a value of <code>undefined</code>. This means that they can be accessed and assigned before their declaration in the code.
For example:
<pre><code class="lang-javascript">cssCopy codeconsole.log(a); // Logs "undefined"
var a = 10;
</code></pre>
In this code, the variable <code>a</code> is declared using <code>var</code>, and even though it's not assigned a value until the second line, it can still be accessed and will return <code>undefined</code>.
This is because <code>var</code> variables are not subject to the TDZ, and their declaration is effectively moved to the top of the scope by the JavaScript engine during runtime. This behaviour can lead to unexpected results and can make it harder to reason about the code.
Therefore, it's generally recommended to use <code>let</code> and <code>const</code> instead of <code>var</code>, as they provide better scoping and prevent issues such as variable hoisting and the TDZ.

The Temporal Dead Zone (TDZ) only applies to variables declared with `let` and `const` keywords in JavaScript, and not to variables declared with `var`.

In JavaScript, variables declared with `var` are hoisted to the top of their respective scopes and are initialized with a value of `undefined`. This means that they can be accessed and assigned before their declaration in the code.

For example:

```javascript
cssCopy codeconsole.log(a); // Logs "undefined"
var a = 10;
```

In this code, the variable `a` is declared using `var`, and even though it's not assigned a value until the second line, it can still be accessed and will return `undefined`.

This is because `var` variables are not subject to the TDZ, and their declaration is effectively moved to the top of the scope by the JavaScript engine during runtime. This behaviour can lead to unexpected results and can make it harder to reason about the code.

Therefore, it's generally recommended to use `let` and `const` instead of `var`, as they provide better scoping and prevent issues such as variable hoisting and the TDZ.

Relation of temporal dead zone with var keyword .