为什么现在大家开发Angular应用都不用$scope改用this了?

Question

我想知道这样有什么优点吗?还是为了什么？比如下面这段代码: function DemoCtrl ($timeout, $q, $log) {    var self = this;    self.simulateQuery = false;    self.isDisabled    = false;    // list of `state` value/display objects    self.states        = loadAll();    self.querySearch   = querySearch;    self.selectedItemChange = selectedItemChange;    self.searchTextChange   = searchTextChange;    self.newState = newState;}