JavaScript 排名排行榜

问题描述

[
  [ 'UserA',490 ],[ 'UserC',175 ],[ 'UserD',67 ],[ 'UserB',26 ]
]

我如何根据排行榜给他们排名？例如。 UserA 在第 1 位，UserC 在第 2 位，依此类推

它看起来像这样：

UserA: Rank 1
UserC: Rank 2
UserD: Rank 3
UserB: Rank 4

解决方法

使用对象并使用排序函数对其进行排序

const results = {
  'UserA': { points: 490 },'UserB': { points: 26  },'UserC': { points: 175 },'UserD': { points: 67  }
}
const rank = Object.entries(results)
  .sort(([,a],[,b]) => b.points - a.points)
  .map((item,i) => {
    results[item[0]].rank = (i + 1)
    console.log(item[0],results[item[0]].rank)
    return `${item[0]}'s Rank: ${i+1}`
  })
console.log(results)

const findUserRank = user => rank.filter(entry => entry.includes(user))
const getUserRankOnly = user => results[user].rank
const getRankUser = ranking => Object.entries(results).filter(([key,val]) => val.rank===ranking).map(([key]) => key)


console.log("Users containing 'User':",findUserRank('User').join("\n"))
console.log("User with rank #3",getRankUser(3)[0])
console.log("UserC's rank:",getUserRankOnly('UserC'))

与嵌套数组相同

const results = [
  [ 'UserA',490 ],[ 'UserC',175 ],[ 'UserD',67 ],[ 'UserB',26 ]
];
const rank = results.slice(0)
  .sort(([,b]) => b - a)
  .map((item,i) => `${item[0]}'s Rank: ${i+1}`);

const getUserRank     = user => rank.filter(entry => entry.includes(user))
const getUserRankOnly = user => rank.filter(entry => entry.includes(user))[0].split(": ")[1]
const getRankUser     = ranking => rank.filter(entry => entry.endsWith(ranking))[0].split("'")[0]


console.log("Users containing 'User':",getUserRank('User').join("\n"))
console.log("Users containing 'UserC':",getUserRank('UserC')[0])
console.log("User with rank #3",getRankUser('3'))
console.log("UserC's rank:",getUserRankOnly('UserC')[0])