is equal !
Array is equal not array:
The abstract equality operator converts both sides to numbers to compare them, and both sides become the number 0 for different reasons. Arrays are truthy, so on the right, the opposite of a truthy value is false, which is then coerced to 0. On the left, however, an empty array is coerced to a number without becoming a boolean first, and empty arrays are coerced to 0, despite being truthy.
Here is how this expression simplifies:
+ == +!;
0 == +false;
0 == 0;
See also  is truthy, but not true.