Check For An Key In Object in JS and PHP
Coming From Python this felt a little funny since Python has so many nice features for looking up keys and setting defaults etc.
Check if object has a key in JavaScript
https://stackoverflow.com/questions/455338/how-do-i-check-if-an-object-has-a-key-in-javascript
myObj.hasOwnProperty('key');
check if array has a key in PHP
array_key_exists('filename', $resourcePairedValue)