- Write a function `add` that uses a closure that performs addition on arguments in two separate function calls. code example

Example 1: How to create a function in javascript

function addfunc(a, b) {
  return a + b;
  // standard long function
}

addfunc = (a, b) => { return a + b; }
// cleaner faster way creating functions!

Example 2: variable used in a function can be used in another function js

function medium(){
         var user1=new collector(one,two);
         var user2=new collector(one,two);
         login(user1,user2);

       }

      function login(user1,user2){
        var u1=user1.username;
        var u12=user1.password;
        var u2=user2.username;
        var u22=user2.password;
      }