Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<body ng-app="">

<input ng-focus="count = count + 1" ng-init="count=0" />

<h1>{{count}}</h1>

<p>This example will increase the value of the variable "count" every time the input field gets focus.</p>

</body>
</html>