I am not sure what's up with the first two. But in the latter one, I believe the array is being coerced to a string, which is its contents separated by commas,

I am not sure what's up with the first two. But in the latter one, I believe the array is being coerced to a string, which is its contents separated by commas, so in this case just "42". Then either the left-hand 42 is coerced to a string or the right-hand "42" is coerced to a number, I'm honestly not sure. It hasn't been all that long since I read the spec about this, either. Sheesh.