javascript - 寻找数组的众数？ JavaScript

Question

好吧，我只知道如何从数组中获取一种模式..但如果它们出现的次数相同，我希望得到 2、3 或更多。这是代码:

var frequency = {};  // array of frequency.
var maxFreq = 0;  // holds the max frequency.

for (var i in array) {
    frequency[array[i]] = (frequency[array[i]] || 0) + 1; // increment frequency.

    if (frequency[array[i]] > maxFreq) { // is this frequency > max so far ?
        maxFreq = frequency[array[i]];  // update max.
        mode = array[i];          // update result.
    }
}

现在，如果我有一个 array = [3, 8, 3, 6, 1, 2, 9];我得到 mode = 3;

但我正在寻找的是 if array = [3, 6, 1, 9, 2, 3, 6, 6, 3, 1, -8, 7];我想要获取 mode = 3, 6;

Answer 1

问题没有说明如何获取模式，但如果我们希望它们位于数组中，我们可以像这样更改代码:

function getModes(array) {
  var frequency = []; // array of frequency.
  var maxFreq = 0; // holds the max frequency.
  var modes = [];

  for (var i in array) {
    frequency[array[i]] = (frequency[array[i]] || 0) + 1; // increment frequency.

    if (frequency[array[i]] > maxFreq) { // is this frequency > max so far ?
      maxFreq = frequency[array[i]]; // update max.
    }
  }

  for (var k in frequency) {
    if (frequency[k] == maxFreq) {
      modes.push(k);
    }
  }

  return modes;
}

alert(getModes([3, 6, 1, 9, 2, 3, 6, 6, 3, 1, -8, 7]));