移除与数组值相等的对象的操作

Question

我有一个对象数组和一个普通数组，如果对象数组中的项等于普通数组中的项，我想要移除它。对我来说这很困惑。

以下是我目前尝试过的：

<code>var countries = 
[
{ChoicesID: 1, ChoicesName : 'afghanistan'},
{ChoicesID: 2, ChoicesName : 'albania'},
{ChoicesID: 3, ChoicesName : 'algeria'},
{ChoicesID: 4, ChoicesName : 'angola'},
{ChoicesID: 5, ChoicesName : 'argentina'},
{ChoicesID: 6, ChoicesName : 'armenia'}
];

var answer = ['afghanistan','albania','algeria'];

var ChoicesName = new Set(countries.map(d => d.ChoicesName));
var NewCountries = [...ChoicesName, ...answer.filter(d => !ChoicesName.has(countries.find(o => o.ChoicesName === answer)))];
console.log(NewCountries );</code>

预期输出应该是这样的：

var NewCountries = 
     [
       {ChoicesID: 4, ChoicesName : 'angola'},
       {ChoicesID: 5, ChoicesName : 'argentina'},
       {ChoicesID: 6, ChoicesName : 'armenia'}
     ];

Answer 1

var countries = 
[
{ChoicesID: 1, ChoicesName : '阿富汗'},
{ChoicesID: 2, ChoicesName : '阿尔巴尼亚'},
{ChoicesID: 3, ChoicesName : '阿尔及利亚'},
{ChoicesID: 4, ChoicesName : '安哥拉'},
{ChoicesID: 5, ChoicesName : '阿根廷'},
{ChoicesID: 6, ChoicesName : '亚美尼亚'}
];

var answer = ['阿富汗','阿尔巴尼亚','阿尔及利亚'];

var NewCountries = countries.filter(o => !answer.includes(o.ChoicesName))

console.log(NewCountries)

像这样？

Answer 2

使用 filter 并删除如果 answer 中存在它。创建一个 answerSet 以进行 O(1) 的查找，否则可以使用 includes，但 includes 的时间复杂度为 O(m)（其中 m 是 answer 数组中的元素数量，n 是 countries 数组中的元素数量）

使用 set
O(m) + O(n).O(1) = O(n)（给定 n>m）

使用 includes
O(n).O(m) = O(nm)

var countries = [{ChoicesID: 1, ChoicesName : 'afghanistan'},{ChoicesID: 2, ChoicesName : 'albania'},{ChoicesID: 3, ChoicesName : 'algeria'},{ChoicesID: 4, ChoicesName : 'angola'},{ChoicesID: 5, ChoicesName : 'argentina'},{ChoicesID: 6, ChoicesName : 'armenia'}];
var answer = ['afghanistan','albania','algeria'];

const answerSet = new Set(answer)

const newCountries = countries.filter(c => !answerSet.has(c.ChoicesName))

console.log(newCountries)