AngularJs Check if Reference is Array

<!DOCTYPE html>
<html lang="en">
<head>
 <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.13/angular.min.js"></script>
 <script>
var myApp = angular.module("myApp", []);
 myApp.controller("myController", function($scope) {
 $scope.html= '';
   var myArray = ['1','3'];
  $scope.checkArray = function() {
	if(angular.isArray(myArray)){
		alert("Is Array");		
	}
  }
   var myArray1 = '';
  $scope.checkArray1 = function() {
	if(angular.isArray(myArray1)){
		alert("Is Array");		
	}else{
		
		alert("Not An Array.");
	}
  }
});
</script>
</head>
<body>  
<div ng-app="myApp">  
<div ng-controller="myController">  
	
    <button ng-click ="checkArray()">Example1 </button>
	<br>
	 <button ng-click ="checkArray1()">Example2</button>
	<br>
	
</div> 
</div>
</body>  
</html>