Angular $watch | returning the item from function

Question

I\'m interested to find out why i always have to do this

$scope.$watch( function() {
   return $scope.someData;
}, function( value ) {
   console.log( value         


        

Answer 1

I guess it's worth mentioning that passing a function to $watch is useful when you want to monitor a condition:

$scope.$watch(function() { 
    return $scope.data.length > 0; 
}, function() {
    // Do something every time $scope.data.length > 0 changes
});

or

$scope.$watch(function() { 
    return $scope.prop1 && $scope.prop2;
}, function() {
    // Do something every time $scope.prop1 && $scope.prop2 changes
});