closure.js

function aClosedClosure(name){
  var lastName = 'Dahlstrom';
  return function(firstNameLocal){
    if(firstNameLocal)
    {
      return firstNameLocal +' '+ lastName;
    }
    else
    {
      return lastName;
    }
  }
}
console.log(aClosedClosure()())
console.log(aClosedClosure()('Olle'))