Namespace VS scope

This sounds like your lesson will soon be leading up to javascript closures and javascript classes. Here is an article i found on closures http://javascriptissexy.com/understand-javascript-closures-with-ease/#

Also here is a small demonstration i made. I not sure my example is expressing closures, as i am still new to the technique. However you can see that the same function name and variable can be used throughout, without overwriting each other https://jsfiddle.net/9s1yhda6/19/

Hope that helps

Ben Aharoni

When you declare a variable like this let myName = 'Dave'; you cannot redeclare that variable again using let. For example, this creates an error:

let myName = 'Dave';
let myName = 'Ben'; // produces an error 

However, you can redefine the value of that variable:

let myName = 'Dave';
myName = 'Ben'; // new vale of myName is 'Ben'

You can even reassign a different type of value to that variable:

let myName = 'Dave';
myName = function(name) {
    return "My name is " + name;;
};

You can use the same identifier (that's the name you give the variable) when declaring different variables as long as they live in their own scope -- like the global scope of the program, or the local scope of a function. For example, there is no problem with this code, even though the same identifier is used twice:

let myName = 'Dave'; // global scope
let sayFrank = function() {
  let myName = 'Frank'; // no error, local scope
  return myName;
};
console.log(myName); // "Dave"
console.log(sayFrank()); "Frank"

It's OK because the two myName variables live in different scopes. Check out this video Variable Scope for a refresher on scope.

For a more in-depth discussion of how variables live in different scopes check out this workshop: Understanding Closures in JavaScript.