Empty Array is True

There was a stage when a code like this was written in our Rails app

user = User.where(name: "John")

if user

    something.....

end

The question is will the something get executed only if there is a user named John in database, or it gets executed every time. Sadly it gets executed all the time.

So why it happens. Try this in your irb

>> puts "A" if []
A
=> nil
>> puts "A" unless [].empty?
=> nil
>> puts "A" if [].first
=> nil

So if you see, when we pass an  empty array to a condition, its always true!!!

You must remember it like this, even though a rack or shelf is empty, the shelf itself is a object, so its present, its the truth. In the next two examples, I have shown how to check and make things false if array is empty. So happy coding!

I think you can avoid all the array stuff hassel if you use the following type of code in Rails

user = User.find_by(name: "John")

if user

    something.....

end

OR, this one

user = User.where(name: "John").first

if user

    something.....

end

So. Enjoy life. Happy Coding.