true

false

Syntax error

В первом выражении ошибка, что еще за «!!» ??

['Hello', 'World']

[ƒunction() {...}]

['Hello', 'World', ƒunction() {...}]

Undefined

Referance error

[1, 2]

2

[-2, -1, 1, 2]

4

['three', 'two', 'one']

['one', 'two', 'three']

undefined

Syntax Error

20

21

20.7

20.73

true

false

0

-1

[1, 2, 3]

[[2], [4], [6]]

[2, 4, 6]

Такого метода нет

['one', 'two', 'three']

['one', 'two', 'three', 'four']

['two', 'three', 'four']

4

[1, 2, [3, 4]]

[1, 2, 3, 4]

1, 2, 3, 4

[1, 2, [3], [4]]

{ value: 42 }

42

{}

TypeError: Cannot define property