The isUndefined() method in AngularJS basically checks if a reference is defined or not. This method will return True if the reference passed inside the function is not defined or undefined, else it will return False.

Syntax

angular.isUndefined(value)

Example − Check if the reference isUndefined or not

Create a file "isUndefined.html.3" in your Angular project directory and copy-paste the following code snippet.

   
      

      
   

   
      

         Welcome to Tutorials Point
      
      
AngularJS | angular.isUndefined()

      

         Name: {{name}}
         


         {{isUndefined}}
         


         Name: {{name2}}
         


         {{isUndefined1}}
      

      
      
   

Output

To run the above code, just go to your file and run it as a normal HTML file. You will see the following output on the browser window.

In the code, $scope.name is defined, whereas $scope.name2 is not undefined. Hence, we got this output.