如何将多个数组中给出的输入分组，如[key1，“value1”，key2，“value2”，...]？

Question

前几天我得到了这个问题，令人惊讶的是它为我的逻辑思维创造了很多问题。

我们有三个简单的数组：

var countries = [1, "DK", 2, "USA", 3, "Sweden"]; 
var languages = [2, "English", 1, "Danish", 3, "Swedish"]; 
var population = [3, 8000000, 1, 6000000, 2, 3000000000]; 

输出应该是什么样子的控制台日志是这样的：

// In USA people speak English and there live 300000000 people 
// In DK people speak Danish and there live 6000000 people 
// In Sweden people speak Swedish and there live 8000000 people 

现在有人告诉我，它可以用一个for循环来解决，但我陷入了如何获得数字的位置，然后保存这些数字，所以我可以从其他两个数组中选择它们。

它必须是动态的，所以如果我添加更多元素到数组中，它会自动生成像上面提到的三个句子。

这是我从老师那里得到的，所以输入数组必须保持那样。每个数字在升序后都有一个字符串，这就是我们必须弄清楚的模式，所以它看起来像我上面评论过的文字。

Answer 1

你肯定需要使用多个循环。

除非你想改变你的数据（见乔治回答）的结构，这样的事情应该工作：

for (var i = 0; i < countries.length; i+=2) { 
    var countryId = countries[i]; 
    var countryName = countries[i+1]; 
    var countryLanguage, countryPopulation; 
    for (var j = 0; j < languages.length; j+=2) { 
    if (languages[j] == countryId) countryLanguage = languages[j+1]; 
    } 
    for (var j = 0; j < population.length; j+=2) { 
    if (population[j] == countryId) countryPopulation = population[j+1]; 
    } 
    console.log("In " + countryName + " people speak " + 
       countryLanguage + " and there live " + 
       countryPopulation + " people"); 
} 

Answer 2

你的问题是奇怪的数据结构。它转换为东西可以一起工作：

var countries = [1, "DK", 2, "USA", 3, "Sweden"]; 
 
var languages = [2, "English", 1, "Danish", 3, "Swedish"]; 
 
var population = [3, 8000000, 1, 6000000, 2, 3000000000]; 
 

 
var data = {}; 
 

 
function addArray(key, ary) { 
 
    
 
    for (var i = 0; i < ary.length; i += 2) { 
 
    var j = ary[i]; 
 
    data[j] = data[j] || {}; 
 
    data[j][key] = ary[i + 1]; 
 
    } 
 
} 
 

 
addArray('country', countries); 
 
addArray('language', languages); 
 
addArray('population', population); 
 

 
document.write("<pre>" + JSON.stringify(data,0,3)); 
 

这应该是显而易见如何从这个对象的输出。

Answer 3

与二维数组变化的逻辑就像

var array = [["DK","English","8000000"],["USA","Danish","6000000"],["Sweden","Swedish","2000000"]]; 

从，你可以很容易地找到你的价值。

Answer 4

console.log("In USA people speak " + languages[(languages.indexOf(countries[countries.indexOf("USA")-1]) 
+ 1)] + " and there live " + 
population[(population.indexOf(countries[countries.indexOf("USA")-1])+ 1)] + " people"); 

注意：这是一个不需要操作数据的解决方案！ 这适用于第一个，其他人将是相同的。不知道是否有更好的方法，但这是我的第一本能......

Answer 5

虽然IE8及以下不支持Array.indexOf，你可以试试：

var countries = [1, "DK", 2, "USA", 3, "Sweden"]; 
var languages = [2, "English", 1, "Danish", 3, "Swedish"]; 
var population = [3, 8000000, 1, 6000000, 2, 3000000000]; 

var size = countries.length/2; 

for (var i = 1; i <= size; i++) 
{ 
    var country = countries[countries.indexOf(i) + 1]; 
    var lang = languages[languages.indexOf(i) + 1]; 
    var pop = population[population.indexOf(i) + 1]; 

    console.log("In " + country + " people speak " + lang + " and there live " + pop + " people"); 
}