JavaScript中的自定义数组排序

Question

我有任务 需要通过以下方式对字符串（城市）数组进行排序：

• 数组中的第一个城市是随机选择的。
• 下一个城市必须以上一个城市的最后一个字母开头。
• 如果没有这样的城市，请再次选择随机城市。

问题是：我应该使用哪种类型的循环以及如何实现排序？ 我应该使用Array.sort（）方法，以及如何将城市的原始数组动态转换为新数组。 我应该使用哪种Array.prototype方法？

let cities = [ "New York", "Tokio", "Moscow", "London", "Los Angeles", "Paris", "Berlin", "Madrid", "Kiev", "Oslo", "Barcelona", "Washington", "Ankara", "Rome", "Prague", "Amsterdam", "Minsk"];

function getRandomCity(arr) {
    return arr[Math.floor(Math.random()*arr.length)];
}

function sort(arr) {
    let unsortedArray = [...arr]; 
    let sortedArray = [];
}

Answer 1

 let cities = ["New York", "Tokio", "Moscow", "London", "Los Angeles", "Paris", "Berlin", "Madrid", "Kiev", "Oslo", "Barcelona", "Washington", "Ankara", "Rome", "Prague", "Amsterdam", "Minsk"]; function getRandomCity(arr) { return Math.floor(Math.random() * arr.length); } function sort(arr) { let unsortedArray = [...arr]; let sortedArray = []; let char = "!"; // choose will take an index and then push the city at that index into the sortedArray and remove it from unsortedArray and store the last letter of that city in char (uppercased) function choose(index) { let city = unsortedArray.splice(index, 1)[0]; sortedArray.push(city); char = city.charAt(city.length - 1).toUpperCase(); } choose(getRandomCity(unsortedArray)); // first of all, choose a random city while (unsortedArray.length) { // while there still cities let index, test = unsortedArray.some(function(c, i) { // check if there is a city that begin with char index = i; // store the index in the process return c.charAt(0) === char; }); if(test) // if we found a city choose(index); // choose it else // if not choose(getRandomCity(unsortedArray)); // choose a random one } return sortedArray; } console.log(sort(cities)); 

Answer 2

您可以使用Array.prototype.slice() ， Array.prototype.splice() ，递归从数组中返回随机元素，或者返回具有第一个字母（不区分大小写）的元素，与上一个元素相同

 let cities = [ "New York", "Tokio", "Moscow", "London" , "Los Angeles", "Paris", "Berlin", "Madrid" , "Kiev", "Oslo", "Barcelona", "Washington" , "Ankara", "Rome", "Prague", "Amsterdam", "Minsk"]; let copyCities = cities.slice(0); function getRandomCity(copy, len, res = []) { let curr, next; if (res.length > 0) { next = copy.filter(function(city) { var prev = res[res.length -1].slice(-1); return new RegExp(city[0], "i").test(prev) }); if (next.length) next = copy.splice(copy.indexOf(next.shift()), 1); } if (copy.length === len || !next.length) { res.push(copy.splice(Math.floor(Math.random()*copy.length), 1)[0]); } else { res.push(next[0]); } if (res.length < len) { return getRandomCity(copy, len, res) } else { return res } } var _cities = getRandomCity(copyCities, cities.length); console.log(_cities);