Passing read-only values as function parameters and not relying on the scope/this/vm available on the closure

controllers.js

/**
  It is always a better idea to pass the readable items as function parameters when defining functions 
  on the scope/this/vm. Although the change is very subtle but as the code base grows bigger, this helps
  identifying whats being read and written when a function is handling multiple things. Also, when calling
  the function from the view, putting in the parameters there an then keeps the code readable and identifiable.
  e.g.
  <ul>
    <!-- Clearly identifiable that the user being passed in is being selected -->
    <li ng-repeat="user in users" ng-click="vm.select(user)"></li>
  </ul>
**/
angular.module('app', [])
  .controller('appCtrl', function(){
    var vm  = this;
    vm.state = false;
    vm.toggle = toggle;

    ////////////////
    /**
      This function works and is perfectly fine but writing it this way reduces the reusability of
      the function as the function is dependent on the environment i.e. the scope/this/vm available
      through the closure. This is not a BAD thing in anyway but it is a less cleaner and less reusable
      way to define a function on the scope/this/vm.
    **/
    function toggle(){
        vm.toggle = !vm.toggle;
    }
        
    /**
      The function below has a few advantages over the one defined above. 
      1) Its a lot cleaner and has a clearly defined API
      2) You can create a get/set with a single function this way
      3) Code is more readable as the readonly values are passed in via arguments
        and writeables are accessed via the closure
    **/
    function switch(state){
      vm.toggle = state
    }
  });