Squarespace solves this problem using the ".equal" predicate (I can't post the link due to not enough rep. points):
{.equal? foo "bar"}
<h1>It's true</h1>
{.or}
<h1>Not true</h1>
{.end}
where foo is the key to a value provided within the JSON data. If you only want the "false/not-equal" part of it, then it could be condensed to:
{.equal? foo "bar"}{.or}<h1>Not true</h1>{.end}
Now, in cases where "bar" contains a space, you'll need to use a different character than a space as a delimiter. From the Squarespace Forums:
The solution then is to specify any other character as a delimiter
(one that won't be used in any other part of the string). For example,
this will work:
{.equal?:categoryFilter:"Family Law"}
You can see that instead of using a space after .equal?, I've used a :
(colon). That way, the space in your second argument "Family Law" is
treated correctly and not attempting to delimit the words into two
separate arguments.
Note: to see that data that is provided for a page, add "?format=json-pretty" to the url. Here's an example.