Can you explain hoisting in JavaScript?

Can you explain hoisting in JavaScript?

Sure! Hoisting is a JavaScript mechanism where variables and function declarations are moved to the top of their containing scope during the compile phase.

Does that mean I can use variables before they are declared?

Yes, you can use variables before they are declared, but only their declaration is hoisted, not their initialization. This can lead to undefined values.

Can you give me an example of hoisting?

Of course! For example:

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

In this case, the declaration of x is hoisted, but the assignment happens at runtime.

What about function hoisting?

Function declarations are also hoisted. You can call a function before it's defined in the code, like this:

myFunction(); // 'Hello!'
function myFunction() {
  console.log('Hello!');
}