Ok some of these I understand but what the fuck. Why.

Edit: ok I have a theory. == checks equality without casting to any types, so they're not equal. But < and > are numeric operations, so null gets cast to 0. So <= and >= cast it to 0, and it's equal to 0, so it's true.

POV: you don't understand type coercion

This one is one of my favourite JS quirks:

This build on that humorously: https://www.destroyallsoftware.com/talks/wat

I wrote an exam about this stuff yesterday.

In J's equality is usually checked in a way that variables are casted to the type of the other one. "25" == 25 evaluates to truey because the string converted to int is equal to the int and the other way around.

You can however check if the thing is identical, using "25" == 25 which skips type conversion and would evaluate as false.

I assume the same thing happens here, null is casted to int, which gets the value 0.

Can someone explain this? I mean, the last result. Usually I can at least understand Javascript's or PHP's quirks. But this time I'm stumped.

I know it’s a joke, but it’s an old one and it doesn’t make a lot of sense in this day and age.

Why are you comparing null to numbers? Shouldn’t you be assuring your values are valid first? Why are you using the “cast everything to the type you see fit and compare” operator?

Other languages would simply fail. Once more JavaScript greatest sin is not throwing an exception when you ask it to do things that don’t make sense.