var myApp = angular.module('myApp', []);

myApp.controller('oneController', ['$scope', '$rootScope', function ($scope, $rootScope) {
 // 局部的变量，只有在oneController中才会显示
 $scope.one_language = 'Python';

 // 全局的变量，都可以调用
 $rootScope.language = 'Go';
}]);

myApp.controller('twoController', ['$scope', function ($scope) {
 // 局部的变量，只有在twoController中才会显示
 $scope.two_language = 'Java';
}]);

<span ng-app="myApp">
  <style>
    div{margin-top: 15px;border: 2px solid rebeccapurple;width: 400px;}
  </style>
  <div>
    <h3>我是全局变量language: {{ language}}</h3>
  </div>
  <div ng-controller="oneController">
    <h3>我是one_language局部变量: {{ one_language}}</h3>
  </div>
  <div ng-controller="twoController">
    <h1>twoController</h1>
    <h3>我是two_language局部变量: {{ two_language }}</h3>
    <h3>我是one_language局部变量: {{ one_language}}</h3>
    <h3>我是全局变量language: {{ language }}</h3>
  </div>
</span>