title: Angular JS : $Scope.Apply()
body: <p>I want to know more about $scope.apply() in real time usage.
  How many times can we use $scope.apply() in a controller?</p>
  
  <p>For example, I have some events like ng-click() , ng-change(), ng-blur() etc. All events are in the same controller. For each and every event, should i use $scope.apply()? If yes, I am getting error : </p>
  
  <pre><code>Error: [$rootScope:inprog] [http://errors.angularjs.org/1.2.15/$rootScope/inprog?p0=%24apply][1]
  at Error (native)
  </code></pre>
  
  <p>I have read in this forum that removing the addition $scope.apply() will resolve the issue. </p>
  
  <p><a href="https://stackoverflow.com/questions/23128220/angularjs-scope-apply-gives-this-error-error-rootscopeinprog">angularjs $scope.$apply() gives this error: Error: [$rootScope:inprog]</a></p>
  
  <p>I implemented the same solution of removing multiple $scope.apply() from the code. The errror is gone, but I want to know how and why?</p>
  
  <p>Can anyone please explain.</p>
  
  <p>Thanks in advance. </p>