angularjs没有返回php数据,尝试了一切

I am learning Angularjs and i am stuck with getting data from PHP file.

<head>
  <script>
    var app = angular.module("new",[]);
    app.controller("control",function($scope,$http){
      $http.get("index.php").then(function(response) {
        $scope.database = response.data;
      });
    });
  </script>
</head>
<body ng-app="new">
  <div ng-controller="control">
    <h1>{{database}}</h1>
  </div>
</body>

This the angular script i wrote. My php code is very simple

<?php
  header("Access-Control-Allow-Origin: *");
  header("Content-Type: application/json; charset=UTF-8");
  echo "How are you?";
?>

I am not able to get php data onto my html file using angularJS. I checked the code twice and nothing seem to be missing. I even tried json_encode(). Did i miss something?

Before all check you php file in right palace using console

In you php code

<?php
  header("Access-Control-Allow-Origin: *");
  header("Content-Type: application/json; charset=UTF-8");
  echo json_encode("How are you?");
  exit();
?>

And in you controller

$http.get("call.php").then(function(response) {
    $scope.database = response.data;
  });