$apply() in AngularJS

https://www.tutlane.com/tutorial/angularjs/angularjs-apply-function

$scope.$apply(function () {
  //Your Code.
});

Different ways to use '$apply()'
1. 
  $scope.$apply(function () {
    $scope.val1 = 'tutlane.com';
  });

2.
  $scope.$apply('val1 = "tutlane.com"');
 
3.(Recommended)  
  $scope.$apply(function (scope) {
    scope.val1 = 'tutlane.com';
  });