<!DOCTYPE html>
<html>
<script src="/lib/angular-1.4.8.min.js"></script>
<body>
<div ng-app="myApp" ng-controller="myCtrl">
<p>{{ x1 }}</p>
<p>{{ x2 }}</p>
</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.x1 = "JOHN";
$scope.x2 = angular.isNumber($scope.x1);
});
</script>
</body>
</html>