console.log(123) === 123, console.log(123) === undefined

[,,,].length

[, a, b, c] = 'foo'; a == b; a == c

42.888.toFixed(2)

![0][1] == [1][0], [0][1] == [1][!0]

[] > [], [] >= []

a = 10; if (a = 5) { b = 0 } else { b = 1 }

(+!'' == !''), (+!'' + !'')

1/0, 1//0

r = new RegExp('A', 'gi'); r.test('A'); r.test('A');

"JavaScript" > "Java", "1" > "A"

++[0][0], ++[[]][+[]]

{} == {}, !{} == !{}

"".split("").length, "".split(" ").length

f() {if(!f.a) f.a=1; return f.a++;}; f()+f()*f()

! + 0, ! + 1

null + 0

[] + []

'' && -0

parseInt(0.0000005)

'' - 1