Checking for an object, based on a string, using Twig Is there a way—using Twig—to check if a variable is set based on a string of the same name?

In this example below, editLink.object is a string with the value of "entryAlias". I want to check to see if a variable, entryAlias, has been set and to see if it's an entry.

{% if "#{editLink.object}" is same as(editLink.object) %}
    it workes
{% else %}
    not so much
{% endif %}


I've looked into same as and is, but I think the problem I'm having is converting the string to an object. Also, I'm pretty sure this can just be done using PHP, but I'd like to see if it can be done within Craft's Twig so this can be cached as part of a template.
After a Slack conversation with @carlcs, we discovered another slick solution...

{{ 'myVariable' in _context|keys }}



The in operator works much like PHP's in_array function.
The keys filter works just like PHP's array_keys function.