Deregister an AngularJS $watch Expression

As you know $watch registers a listener callback that is executed whenever the watch expression changes.

The $watch function returns a deregister function. Calling this deregister function will deregister the $watch expression

Here is an example on registering and deregistering the $watch expression

//registering the $watch listener. It returns a deregister function

var deregister = $scope.$watch('name', function(newValue, oldValue) {

  //code here

});

//calling the deregister function

deregister();