我不知道怎么给我们js过滤索引

Question

const arrayRcp = ["ROCK", "Scissors", "ROCK", "Scissors"]
const user = ["par1", "par2", "par3", "par4"]
const winner = arrayRcp.filter(item => item == 'ROCK' )
const winnerUser = arrayRcp.filter(function(item,index) {...???} )

我想计算获胜者的ROCK指数到winnerUser。然后我不知道。。。？？？如何使用过滤索引的功能请帮助我…

由于ROCK索引0和2出现在arrayRcp中，我想知道如何通过过滤器获得par1和par3，就像用户中的ROCK索引一样。

Answer 1

试试这个：

const arrayRcp = ["ROCK", "Scissors",  "ROCK", "Scissors"]
const user = ["par1", "par2", "par3", "par4"]
const winner = arrayRcp
.map((item, index) => item === 'ROCK' && index)
.filter(Number.isFinite)
const winnerUser = user.filter(function(_, index) {
return this.indexOf(index) >= 0
} , winner)
console.log(winnerUser)