前端隐式判断语句

前端js的判断，下面这些有多少你了解

let a = ({} + {})

let b = 2 * {}

let c = [] == !{}

let d = !!{}

let e = !!undefined

let f = NaN==NaN

let g = {}=={}

let h = '1' + 1

let i = 5 - undefined

let j = 5 - '1'

console.log(a,b,c,d,e,f,g,h,i,j)  //  [object Object][object Object] NaN true true false false false 11 NaN 4