在 Javascript 4 维数组中查找重复项

Question

抱歉，我错误地描述了我的问题：

如果在这样的调用中参数值为“macOS” -> countDuplicate(operatingSystem, "macOS");

函数必须return9的个数。其他值同理(Windows, Unix...)。

谢谢！

let operatingSystem = [
  ["macOS", "Windows", "Unix"],
  ["macOS", ["Windows", "Unix", "macOS"], "Unix"],
  [["macOS", "Windows", "Unix"], "Windows", "Unix"],
  ["Unix", "macOS", ["Windows", "Unix", "macOS"]],
  [["macOS", "Windows", ["Unix", "Windows", "macOS"]], "Windows", "Unix"],
  [["Linux", "Android", ["Unix", "Windows", "macOS"]], "Windows", "Unix"],
];

function countDuplicate(array, arg) {
  let count = 0;

  for (let i = 0; i < operatingSystem.length; i++) {
    for (let j = 0; j < operatingSystem[i].length; j++) {
      for (let k = 0; k < operatingSystem[i][j].length; k++) {
        for (let l = 0; l < operatingSystem[i][j][k].length; l++) {
          let str = operatingSystem[i][j][k][l];
          if (str.indexOf(arg) > -1) {
            count += 1;
            break;
          }
        }
      }
    }
  }
  console.log("There is " + count + " of " + arg + " similar items in this array.");
}
countDuplicate(operatingSystem, "macOS");

Answer 1

首先你 flat() 多维数组然后使用这个解决方案：

let operatingSystem = [
  ["macOS", "Windows", "Unix"],
  ["macOS", ["Windows", "Unix", "macOS"], "Unix"],
  [["macOS", "Windows", "Unix"], "Windows", "Unix"],
  ["Unix", "macOS", ["Windows", "Unix", "macOS"]],
  [["macOS", "Windows", ["Unix", "Windows", "macOS"]], "Windows", "Unix"],
  [["Linux", "Android", ["Unix", "Windows", "macOS"]], "Windows", "Unix"]
];

let counts = {};

operatingSystem.flat(4).forEach(function (x) { counts[x] = (counts[x] || 0) + 1; });

console.log(counts);

let sum = 0;
Object.values(counts).forEach(x => sum += x)

console.log(`The total sum is: ${sum}`)

Answer 2

您可以使用递归来计算所有元素。你也可以做一个平面阵列。

在递归中，如果元素是数组迭代并调用每个值，否则将添加到映射。

let operatingSystem = [
  ["macOS", "Windows", "Unix"],
  ["macOS", ["Windows", "Unix", "macOS"], "Unix"],
  [["macOS", "Windows", "Unix"], "Windows", "Unix"],
  ["Unix", "macOS", ["Windows", "Unix", "macOS"]],
  [["macOS", "Windows", ["Unix", "Windows", "macOS"]], "Windows", "Unix"],
  [["Linux", "Android", ["Unix", "Windows", "macOS"]], "Windows", "Unix"],
];

function countDuplicate(array, res = {}) {
  if (typeof array === "object") {
    array.forEach((x) => countDuplicate(x, res));
  } else {
    if (!res[array]) res[array] = 0;
    res[array]++;
  }
}
let res = {};
countDuplicate(operatingSystem, res);

console.log(res);

console.log(Object.entries(res));

Answer 3

这是一个简单的递归。我们可以从一个值列表和一个目标开始，然后扫描这些值，为每个值添加到我们的运行计数器。如果该值是一个数组，我们将使用相同的目标对其进行重复。否则，如果它匹配目标，我们添加 1，否则不添加任何内容。它可能看起来像这样：

const countDuplicate = (xs, t) => 
  xs .reduce ((c, x) => c + (Array .isArray (x) ? countDuplicate (x, t) : x == t ? 1 : 0), 0)

const operatingSystem = [["macOS", "Windows", "Unix"], ["macOS", ["Windows", "Unix", "macOS"], "Unix"], [["macOS", "Windows", "Unix"], "Windows", "Unix"], ["Unix", "macOS", ["Windows", "Unix", "macOS"]], [["macOS", "Windows", ["Unix", "Windows", "macOS"]], "Windows", "Unix"], [["Linux", "Android", ["Unix", "Windows", "macOS"]], "Windows", "Unix"]];

['macOS', 'Windows', 'Unix', 'Linux', 'Android', 'Other'] .forEach (
  os => console .log (`${os}: ${countDuplicate (operatingSystem, os)}`)
)

在 Javascript 4 维数组中查找重复项

Find repetition in Javascript 4 dimensional array

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