Question

我有3个阵列：

var countries = ['Montenegro', 'Spain', 'Belgium']
var years = ['2000', '2001', '2002', '2003'];
var death = ['cancer', 'measles'];

和一系列对象：

var values = [
    {country:'Montenegro', year:'2000', death:'cancer', number:'50'},
    {country:'Montenegro', year:'2001', death:'cancer', number:'60'},
    {country:'Montenegro', year:'2002', death:'cancer', number:'70'},
    {country:'Montenegro', year:'2003', death:'cancer', number:'80'},
    {country:'Spain', year:'2000', death:'cancer', number:'NaN'},
    {country:'Spain', year:'2001', death:'cancer', number:'110'},
    {country:'Spain', year:'2002', death:'cancer', number:'120'},
    {country:'Spain', year:'2003', death:'cancer', number:'130'},
    {country:'Belgium', year:'2000', death:'cancer', number:'70'},
    {country:'Belgium', year:'2001', death:'cancer', number:'80'},
    {country:'Belgium', year:'2002', death:'cancer', number:'90.5'},
    {country:'Montenegro', year:'2000', death:'measles', number:''},
    {country:'Montenegro', year:'2001', death:'measles', number:'1'},
    {country:'Montenegro', year:'2002', death:'measles', number:'2'},
    {country:'Montenegro', year:'2003', death:'measles', number:'3'},
    {country:'Spain', year:'2000', death:'measles', number:'2'},
    {country:'Spain', year:'2001', death:'measles', number:'3'},
    {country:'Spain', year:'2002', death:'measles', number:'NaN'},
    {country:'Spain', year:'2003', death:'measles', number:'5'}
];

我想要的是一个完整的对象数组＆＃34;，它包含三个数组中存在的所有可能的值组合。

实际上，

values不包含与以下内容相关的对象：

{country:'Belgium', year:'2003', death:'cancer', ...},
{country:'Belgium', year:'2000', death:'measles', ...},
{country:'Belgium', year:'2001', death:'measles', ...},
{country:'Belgium', year:'2002', death:'measles', ...},
{country:'Belgium', year:'2003', death:'measles', ...}

所以我想得到这个新对象（缺少的数据设置为NaN）：

var valuesComplete = [
    {country:'Montenegro', year:'2000', death:'cancer', number:'50'},
    {country:'Montenegro', year:'2001', death:'cancer', number:'60'},
    {country:'Montenegro', year:'2002', death:'cancer', number:'70'},
    {country:'Montenegro', year:'2003', death:'cancer', number:'80'},
    {country:'Spain', year:'2000', death:'cancer', number:'NaN'},
    {country:'Spain', year:'2001', death:'cancer', number:'110'},
    {country:'Spain', year:'2002', death:'cancer', number:'120'},
    {country:'Spain', year:'2003', death:'cancer', number:'130'},
    {country:'Belgium', year:'2000', death:'cancer', number:'70'},
    {country:'Belgium', year:'2001', death:'cancer', number:'80'},
    {country:'Belgium', year:'2002', death:'cancer', number:'90.5'},
    {country:'Belgium', year:'2003', death:'cancer', number:NaN}, // <--
    {country:'Montenegro', year:'2000', death:'measles', number:''},
    {country:'Montenegro', year:'2001', death:'measles', number:'1'},
    {country:'Montenegro', year:'2002', death:'measles', number:'2'},
    {country:'Montenegro', year:'2003', death:'measles', number:'3'},
    {country:'Spain', year:'2000', death:'measles', number:'2'},
    {country:'Spain', year:'2001', death:'measles', number:'3'},
    {country:'Spain', year:'2002', death:'measles', number:'NaN'},
    {country:'Spain', year:'2003', death:'measles', number:'5'},
    {country:'Belgium', year:'2000', death:'measles', number:NaN}, // <--
    {country:'Belgium', year:'2001', death:'measles', number:NaN}, // <--
    {country:'Belgium', year:'2002', death:'measles', number:NaN}, // <--
    {country:'Belgium', year:'2003', death:'measles', number:NaN} // <--
];

新数组包含24个元素= countries.length * years.length * death.length。

最好的方法是什么？

Answer 1

您可以检查所有可能的组合。使用map循环遍历每个数组并使用find

进行搜索

var countries = ['Montenegro', 'Spain', 'Belgium']
var years = ['2000', '2001', '2002', '2003'];
var death = ['cancer', 'measles'];

var values = [
   {country:'Montenegro', year:'2000', death:'cancer', number:'50'},
   {country:'Montenegro', year:'2001', death:'cancer', number:'60'},
   {country:'Montenegro', year:'2002', death:'cancer', number:'70'},
   {country:'Montenegro', year:'2003', death:'cancer', number:'80'},
   {country:'Spain', year:'2000', death:'cancer', number:'NaN'},
   {country:'Spain', year:'2001', death:'cancer', number:'110'},
   {country:'Spain', year:'2002', death:'cancer', number:'120'},
   {country:'Spain', year:'2003', death:'cancer', number:'130'},
   {country:'Belgium', year:'2000', death:'cancer', number:'70'},
   {country:'Belgium', year:'2001', death:'cancer', number:'80'},
   {country:'Belgium', year:'2002', death:'cancer', number:'90.5'},
   {country:'Montenegro', year:'2000', death:'measles', number:''},
   {country:'Montenegro', year:'2001', death:'measles', number:'1'},
   {country:'Montenegro', year:'2002', death:'measles', number:'2'},
   {country:'Montenegro', year:'2003', death:'measles', number:'3'},
   {country:'Spain', year:'2000', death:'measles', number:'2'},
   {country:'Spain', year:'2001', death:'measles', number:'3'},
   {country:'Spain', year:'2002', death:'measles', number:'NaN'},
   {country:'Spain', year:'2003', death:'measles', number:'5'}
];

var valuesComplete = [countries, years, death].reduce((c, v) => [].concat(...c.map(o => v.map(x => [].concat(o, x)))))
                     .map(o => values.find(v => v.country === o[0] && v.year === o[1] && v.death === o[2]) || {country: o[0],year: o[1],death: o[2],number: NaN})

console.log(valuesComplete);

Answer 2

这是我能想到的。

var countries = ['Montenegro', 'Spain', 'Belgium']
var years = ['2000', '2001', '2002', '2003'];
var death = ['cancer', 'measles'];
var valuesComplete = [];

function getDeathByYearCountry(country, year, disease) {
  //your logic to build the number
  return NaN;
}

countries.forEach(function(country) {
  years.forEach(function(year) { 
    death.forEach(function(disease) {
      valuesComplete.push({
       country: country,
       year: year,
       death: disease,
       number: getDeathByYearCountry(country,year,disease)
      });
    });
  });
});

console.log(valuesComplete.length);
console.log(valuesComplete);

制作一系列对象＆＃34;完成＆＃34;基于其他数组的内容

2 个答案: