Hoisting - var vs let

    /**
     * Hoisting
     * var vs let (and const)
     */
    let log = console.log;

    f();        //undefined function
    log(fe);    //ReferenceError - because we are inside the Temporal DeadZone, as we used let fe
    fe();       //returns an error as the function hasn't yet been assigned to fe

    log(v1);  //undefined variable
    var v1;
    
    log(L1);  //ReferenceError - because we are inside the Temporal DeadZone
    let L1;   //did get hoisted, but the 'undefined' assignment happens at this line
    log(L1);
    
    function f() {
      //function declaration
      //gets hoisted to the top just like var
      log("function f");
      let x;       //to avoid global var called x
      x = "hello"; //global var created called x - bad coding practice, if not declared first using let/var x;
    }

    // function expression - assignment to a variable
    // fe gets hoisted to the top, but function assignment happens here
    let fe = function e() {
      log("function fe");
    };