javascript - Get input value using angularjs -

i'm implementing angular js , trying input box's value , store local storage. input typed user , it's refer ip address.

below html code:

  <div>     <input ng-model="serverip">     <input type="button" class="button" value="apply" ng-click="save()">   </div> 

below js code:

.controller('ctrl', function($scope) {      $scope.save= function() {         console.log($scope.serverip);         localstorage.setitem('serverip', $scope.serverip);     }; }) 

why using above coding, after key in ip address input box, $scope.serverip undefine?

i kinda find out correct answer. have pass serverip in html:

  <div>     <input ng-model="serverip">     <input type="button" class="button" value="apply" ng-click="save(serverip)">   </div> 

and in js file:

.controller('ctrl', function($scope) {      $scope.save = function(serverip) {         console.log(serverip);         localstorage.setitem('serverip', serverip);     }; })