从 HTML 输入字段创建随机 javascript 数组答案

【问题标题】：Creating a Random javascript array from an HTML input field从 HTML 输入字段创建随机 javascript 数组
【发布时间】：2021-10-03 15:26:49
【问题描述】：

我有基本的 HTML 表单，要求输入 1 到 10 之间的数字。基于该数字，我想创建一个新数组。目前，代码显示了新创建数组的警告框，但最终它将是一个显示结果的表格。当前数组有 10 个值，我希望它随机生成一个新数组。我想我拥有它，只是缺少一件事或几件事。

function createRandomArray () {

var numOfGamesElement = document.getElementById("numOfGames");
var numOfGames = numOfGamesElement.value;

var gamesPicked [];

  const boardGames = ["UNO", "Monopoly", "Clue", "Pandemic", "Catan", "Articulate!", "Codenames", "Fallout", "Candy Land", "Scrabble"];


let gamesPicked = boardGames[Math.floor(Math.random() * boardGames.length)];

for(let i = 0; i < numOfGames; i++){
  gamesPicked.push(i);
}
  alert(gamesPicked.join("\n"));
//createTable(gamesPicked)
}

【问题讨论】：

标签： javascript html arrays function

【解决方案1】：

这可行，但没有解决随机函数可以选择重复项的问题。

<!DOCTYPE html>
<head>
<script>
function createRandomArray () {
    var numOfGamesElement = document.getElementById("numOfGames");
    var numOfGames = numOfGamesElement.value;

    const boardGames = ["UNO", "Monopoly", "Clue", "Pandemic", "Catan", "Articulate!", "Codenames", "Fallout", "Candy Land", "Scrabble"];

    var gamePicked;
    var gamesPicked = {};
    for(let i = 0; i < numOfGames; i++){
      gamePicked = boardGames[Math.floor(Math.random() * boardGames.length)];
      gamesPicked[i] = gamePicked;
      alert(gamesPicked[i]);
    }
    // could build table here
}
</script>
</head>

<body>
<label>Number of games (1 to 10):
<input id="numOfGames">
</label>
<button onclick="createRandomArray()">Click Me</button>
</body>

【讨论】：

【解决方案2】：

一个问题是您可能会在随机选择的游戏数组中得到重复项。最好对数组进行洗牌（随机化），然后只获取 X 个项目的slice，就像这样。请注意，我将 numOfGames 值从字符串更改为数字，方法是在其前面加上 +

/* Randomize array in-place using Durstenfeld shuffle algorithm */
function shuffleArray(array) {
    for (var i = array.length - 1; i > 0; i--) {
        var j = Math.floor(Math.random() * (i + 1));
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
}    
const boardGames = ["UNO", "Monopoly", "Clue", "Pandemic", "Catan", "Articulate!", "Codenames", "Fallout", "Candy Land", "Scrabble"];    
function createRandomArray () {
   let numOfGames = +document.getElementById("numOfGames").value || 0;
   let gamesPicked = shuffleArray(boardGames).slice(0, numOfGames)
   alert(gamesPicked.join("\n"));
}

【讨论】：

【解决方案3】：

你可以像这样使用 vanilla JS 来做到这一点

function samples(array, length) {
    var samplesSet = new Set();
    if (array.length < length) {
        throw Error("requested length is greater than given array");    
    }
    while(samplesSet.size < length) {
        samplesSet.add(array[Math.floor(Math.random() * array.length)]);
    }
    return [...samplesSet];
}
function createRandomArray () {

var numOfGamesElement = document.getElementById("numOfGames");
var numOfGames = numOfGamesElement.value;

  const boardGames = ["UNO", "Monopoly", "Clue", "Pandemic", "Catan", "Articulate!", "Codenames", "Fallout", "Candy Land", "Scrabble"];


let gamesPicked = samples(boardGames, numOfGames);
  alert(gamesPicked.join("\n"));
//createTable(gamesPicked)
}

或者像这样使用lodash sampleSize

let _ = require('lodash');

function createRandomArray () {

var numOfGamesElement = document.getElementById("numOfGames");
var numOfGames = numOfGamesElement.value;

  const boardGames = ["UNO", "Monopoly", "Clue", "Pandemic", "Catan", "Articulate!", "Codenames", "Fallout", "Candy Land", "Scrabble"];


let gamesPicked = _.sampleSize(boardGames, numOfGames);
  alert(gamesPicked.join("\n"));
//createTable(gamesPicked)
}

【讨论】：