我该如何为树枝变量var中未定义的内容编写if / else语句？

Question

I'm using twig to declare a var user:

<script type="text/javascript">
   {% if user is defined %}
   var user = {
    example: {{ userjson | raw }}
   };
   {% endif %}
 </script>

This checks to see if a user is logged in, if not my console returns this:

Uncaught ReferenceError: user is not defined

I want to be able to display a message if the user is not defined but I can't think of a way to do that. Right now I have this:

if(user){
    console.log('hello');
} else {
    console.log('undefined');
}



// This checks is the user information
var userId = user.example.id;


console.log(user.example.money);

Answer 1

Ok so I figured this out:

<script type="text/javascript">
   {% if user is defined %}
   var user = {
    example: {{ userjson | raw }}
   };
   {% else %}
   var user = false;
   {% endif %}
 </script>

Then I just check to see if the var user is false, and if it's not then I do something else.