angularJS 为什么 $scope.$watch 不能工作？

Question

我想加个$watch看$scope.data有没有变化，但是不行

[http://jsbin.com/biqesojaqu/1/edit?html,js,console,output][1]

app.html

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>
  <meta charset="utf-8">
  <title>JS Bin</title>
</head>
<body ng-app="App" ng-controller="TestController">
<div>
  <ul>
    <li ng-repeat="item in data"> {{ item.name }}--{{ item.status }}</li>
    <button ng-click="addOnePerson()">ADD</button>
  </ul>
</div>
</body>
</html>

app.js

var App = angular.module("App", []);

App.controller('TestController', function ($scope) {
  $scope.data = [
    {name: 'cc', status: true},
    {name: 'bob', status: false}
  ];
  $scope.name = 'nataila';
  $scope.addOnePerson = function () {
    var personCount = $scope.data.length;
    personCount += 1;
    $scope.data.unshift({name: 'cc'+personCount, status: true});
  };
  $scope.$watch('data', function (){
    console.log('has changed');
  });
});

当我点击按钮时，我认为控制台会输出 has chenged，但它什么都没有请告诉我为什么，在 JSbin

中帮助我很好

Answer 1

对 array 或 object

使用 $watchCollection

$scope.$watchCollection('data', function (){
  console.log('has changed');
});

JSBin

angularJS 为什么 $scope.$watch 不能工作？

angularJS why $scope.$watch cant't work?

javascript

angularjs

angularjs-scope

angularjs-watch