difference var and let in javascript code example

Example 1: var vs let js

let: //only available inside the scope it's declared, like in "for" loop, 
var: //accessed outside the loop "for"

Example 2: let and var difference

function run() {
  var foo = "Foo";
  let bar = "Bar";

  console.log(foo, bar);

  {
    let baz = "Bazz";
    console.log(baz);
  }

  console.log(baz); // ReferenceError
}

run();