Lexical scope/closures in javaScript

Question

I understand functions in \'js\' have lexical scope (i.e. functions create their environment (scope) when they are defined not when they are executed.)

funct         


        

Answer 1

    function f1() {
          var a = 1;
          f2();
          }

    function f2() {
       return a;
    }
    f1(); // a is not defined

1. f2(); does not knows about the a,because you never passed 'a' to it,(That's Scope are created when the functions are defined).Look function f2() would have been able to acess a if it was defined inside f1();[Functions can access the variables in same scope in which they are "DEFINED" and NOT "CALLED"]

   function f() {
      var b = "barb";
      return function(){
                        return b;
                       }
   }
   console.log(b); 
   

2. First of all You Need to Call f(); after executing f(); it would return another function which needs to be executed. i.e

   var a=f();
   a();
   

   it would result into "barb" ,In this case you are returning a function not the var b;

   function f() {
      var b = "barb";
      return b;
                };
   
   console.log(f());
   

   This would print barb on screen