在循环内随机化二维数组

问题描述

我将数据存储在包含国家名称和首都的二维数组中。我想遍历数组，并显示每个国家的名称，以及其他国家（而不是当前国家）的首都（将以随机顺序排序）。在循环内部，使用函数shuffle()对国家的首都进行随机排序。但是此功能似乎导致显示重复的数组项（例如，一个国家（在下面的循环中，在arr[i][0]中，像Vietnam一样，错误地出现了两次）：

var masterlist = [
  ["Indonesia","Jakarta"],["Malaysia","Kuala Lumpur"],["Philippines","Manila"],["Singapore","Singapore"],["Thailand","Bangkok"],["Vietnam","Hanoi"],["China","Beijing"],["Japan","Tokyo"],["South Korea","Seoul"],["Taiwan","Taipei"]
];

/* Randomize array in-place using Durstenfeld shuffle algorithm */
function shuffle(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;
  }
  return array;
}

for (var i = 0; i < masterlist.length; i++) {
  //console.log("masterlist[i][0]",masterlist[i][0]);

  var arr = shuffle(masterlist); // create a shuffled copy of the array; ERROR here; the shuffle function inside this loop causes duplicate masterlist items
  //console.log(arr[i][0]);

  // save as new array the masterlist with the item's capital removed (ONLY to be used for choosing other nations' capitals in random order):
  var filteredArr = arr.filter(function(e) {
    return e !== arr[i]
  })

  console.log(arr[i][0],filteredArr); // ERROR here; should give unique country,then all other nations' capitals in random order

  var correctItem = arr[i];
  //console.log("correctItem",correctItem);

}

解决方法

这是您需要的吗？

1. 环状国家
2. 对于每个国家/地区，除当前国家/地区外，所有资本均会列为数组
3. 随机播放结果
4. 对国家/地区和首都进行任何操作，在我的示例中，仅是console.log

var masterlist = [
  ["Indonesia","Jakarta"],["Malaysia","Kuala Lumpur"],["Philippines","Manila"],["Singapore","Singapore"],["Thailand","Bangkok"],["Vietnam","Hanoi"],["China","Beijing"],["Japan","Tokyo"],["South Korea","Seoul"],["Taiwan","Taipei"]
];

/* Randomize array in-place using Durstenfeld shuffle algorithm */
function shuffle(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;
  }
  return array;
}

for (var i = 0; i < masterlist.length; i++) {

  var country = masterlist[i][0];
  var countryArr = [];

  for (var j = 0; j < masterlist.length; j++) {
    if (i !== j) countryArr.push(masterlist[j][1]);
  }

  countryArr = shuffle(countryArr);

  console.log({
    [country]: countryArr
  });
}