JavaScript Hoisting?

JavaScript, hoisting is a behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase, before the code is executed. This means that you can use variables and functions in your code before they are declared.

Here's a brief explanation of hoisting:

1. Variable Hoisting:

console.log(x); // undefined
var x = 5;
console.log(x); // 5        

In the above example, the declaration var x; is hoisted to the top, so the first console.log(x); prints undefined.

2.Function Hoisting:

sayHello(); // "Hello, World!"
function sayHello() {
    console.log("Hello, World!");
}        

Function declarations are also hoisted, allowing you to call the function before its declaration in the code.

3. Let and Const:

While var declarations are hoisted, let and const declarations are hoisted as well, but they are not initialized. This is known as the "temporal dead zone," and accessing them before the actual declaration will result in a ReferenceError.

console.log(y); // ReferenceError: Cannot access 'y' before initialization
let y = 10;
        

In terms of type, JavaScript is a dynamically-typed language. This means that variables are not bound to a specific data type, and their type can change during runtime. For example:

let exampleVar = 5; // exampleVar is a number
exampleVar = "Hello"; // Now exampleVar is a string