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<div ng-app=""> 
<p>Language: <input type="text" ng-model="lang"></p> 
<p> 
{{lang}} </p> 
</div> 
try this:
<div ng-app="lang" ng-controller="mylang"> 
My first favorite language: <input type="text" ng-model="firstlang"> <br>
My second favorite language: <input type="text" ng-model="secondlang"> <br>
<br>
My favorite languages: {{firstlang + " " + secondlang}} 
</div>
<script> 
var app = angular.module('lang', []);
app.controller('mylang', function($scope) {
$scope.firstlang= "PHP";
$scope.secondlang= "JAVA";
}); 
</script> 
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