tdz

Temporal Dead Zone (TDZ) is a term used in the context of JavaScript programming, specifically related to the behavior of variables declared using the `let` and `const` keywords introduced in the ES6 (ECMAScript 2015) version of the language.

The Temporal Dead Zone refers to the period between the entry into a scope of a `let` or `const` variable and the actual initialization of that variable. During this time, the variable exists but cannot be accessed. Attempting to do so results in a ReferenceError. This behavior is designed to prevent the use of variables before they are properly initialized, which can help avoid certain types of programming errors.

For example, in the following code snippet, attempting to access the variable `x` before it is declared and initialized results in a ReferenceError because it falls within the TDZ:

```javascript

function example() {

console.log(x); // ReferenceError: Cannot access 'x' before initialization

let x = 10;

}

```

In contrast, variables declared with the `var` keyword do not exhibit this behavior. They are hoisted to the top of their scope and initialized with a default value of `undefined`, making them accessible before their actual declaration in the code.

Understanding the Temporal Dead Zone is crucial for developers working with modern JavaScript, as it affects the way variables are scoped and initialized in the language.