After checking your solution, I can see that you are printing irrelevant messages to the console instead of returning the Boolean results.

Write the function collinearity(x1, y1, x2, y2), which returns a Boolean type depending on whether the vectors are collinear or not.

The example tests also demonstrate that clearly. Also, I suggest you read this before continuing to solve more katas for the sake of better understanding on how things work here. Also, sharing your code with spoiler flag would have been much easier than asking reviewers to find which language you're training on with the relevant code! Kudos ^^

The "View solution" button does not work well and it's not easy to use. To see your solution, I have to a) know what of 13 available languages you attempted and b) I have to solve the kata in this language, which I might not know how to do. It's much easier if you just post your code (properly formatted). Or if you want me to use the "view solution" button, you have to tell what language you use.

"My solution does not work" is not a kata issue.

Show us your solution and we will check what's wrong with it.