Угловая область видимости не работает

Question

Я контроллер, как:

angular.module('app', []) 
.controller('ctrl', ['$scope', function ($scope) { 
$scope.daysPerMonth = new Date(year, month).getDate(); 
}] 
); 

И HTML:

<div ng-app> 

    <h1>How many days has month?</h1> 

    <input ng-model="month" type="text" placeholder="Set a month as number"> 

    <input ng-model="year" type="text" placeholder="Set a year as number"> 

    <p ng-if="year" ng-model="daysPerMonth"> 
    In {{ month }} of {{ year }}, we have {{ daysPerMonth }} days. 
    </p> 

</div> 

Почему он не работает?

https://jsfiddle.net/m7aLdwe1/

Answer 1

попробовать this.you забыл добавить нг-регулятора, и нг-приложение я просто исправить свои ошибки.

var app = angular.module('app', []); 
 
\t app.controller('ctrl',['$scope', function ($scope) { 
 
     
 
     //change your logic to compute ... 
 
     
 
\t }]);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script> 
 
<div ng-app="app" ng-controller="ctrl"> 
 

 
    <h1>How many days has month?</h1> 
 
    
 
    <input ng-model="month" type="text" placeholder="Set a month as number"> 
 
    
 
    <input ng-model="year" type="text" placeholder="Set a year as number"> 
 
    
 
    <p ng-if="year" > 
 
    In {{ month }} of {{ year }} ...... 
 
    </p> 
 
    
 
</div>