How do you find a value stored in a list of variables?

How do you find a value stored in a list of variables?

Would you give an example of what you are trying to do ?

I am making a counter to count the number of likes and there is a video title and I want to know if this is how the title of the video has been added to the list for the number of likes

As per your statement you can try

Is in the list item (value) list (desired list)

Will return true or false

True mean the value is exist, false mean does not