Hoisting variables in JavaScript

Question

I understand Hoisting of variables is done in Java Script. I am unable to get why it outputs as undefined

 do_something()
    {
    var foo = 2;    
    cons         


        

Answer 1

This is how the interpreter sees your code,

do_something() {
 var foo;
 console.log(foo); // undefined
 foo = 2;
}

do_something();

So it is printing undefined. This is a basic of variable hoisting. Your declarations will be moved to the top, and your assignation will remain in the same place. And the case is different when you use let over var.