Array : How to resolve this ' Uncaught TypeError: Cannot convert undefined or null to object '

Array : How to resolve this " Uncaught TypeError: Cannot convert undefined or null to object "
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I promised to reveal a secret feature to you, and now it's time to share it.
This is a YouTube's feature which works on Desktop.
First, Ensure that the video is playing before proceeding.
Next, enter the letters 'awesome' on your keyboard.
The progress bar on YouTube will be altered to a flashing rainbow.

Let me give you a brief introduction of who I am,
Good day, I am Delphi.
I am capable of providing answers to your questions.
Array : How to resolve this " Uncaught TypeError: Cannot convert undefined or null to object "
If you have specific questions that need answers, please don't hesitate to comment or chat with me.
We appreciate your participation, so please feel free to comment below with your answer or insights.
Providing an answer will be acknowledged and appreciated with a 'heart' from me.
" undefined Cannot object Array or to " : How null TypeError: convert resolve to this Uncaught