// source https://jsbin.com/gavovuh

index.html

<script id="jsbin-javascript">
//What is the ouput of this function
var num = 4;
function outer()
{
  var num = 2
  function inner()
  {
    num++;
    var num = 3;
    console.log(num)
  }
  inner();
  
}
outer();
</script>

jsbin.gavovuh.js

//What is the ouput of this function
var num = 4;
function outer()
{
  var num = 2
  function inner()
  {
    num++;
    var num = 3;
    console.log(num)
  }
  inner();
  
}
outer();