Replace string to a function or use $watchCollection, like this:
Using var:
angular.module('TestApp', [])
.controller('MainCtrl', function($scope){
// Object
var settings = {
number: 1,
foobar: 'Hello World'
};
$scope.$watch(function(){ return settings.number; }, function(newValue, oldValue){
console.log('New value detected in settins.number');
});
$scope.$watchCollection(function(){ return settings; }, function(newValue, oldValue){
console.log('New value detected in settings');
});
});
Using $scope:
angular.module('TestApp', [])
.controller('MainCtrl', function($scope){
// Object
$scope.settings = {
number: 1,
foobar: 'Hello World'
};
$scope.$watch('settings.number', function(newValue, oldValue){
console.log('New value detected in $scope.settings.number');
});
});
Example: http://jsfiddle.net/Chofoteddy/2SNFG/
*Note: $watchCollection that is available in AngularJS version 1.1.x and above. It can be really useful if you need to watch multiple values in a array or multiple properties in a object.