javascript - 计算字符串中的字母和数字

Question

我编写的代码适用于字母但不适用于数字我知道这可能有点复杂，但我就是这样做的；它用数字生成有序数组，我不知道为什么

var orderedCount = function(text) {
  let splitted = text.split('');
  let countedLetters = splitted.reduce((AllLetters, letter) => {
    (letter in AllLetters) ? AllLetters[letter]++: AllLetters[letter] = 1;
    return AllLetters
  }, {})
  let result = Object.keys(countedLetters).map((key) => {
    return [(key), countedLetters[key]]
  })
  return result;

};
console.log(orderedCount("abracadabra")); //[['a',5], ['b',2], ['r',2], ['c',1], ['d',1]]
console.log(orderedCount("212")); //[['1',1], ['2',2]]

[['1',1],['2',2]] 

应该是

[['2',2],['1',1]]

Answer 1

可以使用Object.entries将对象转换为数组，使用sort对元素1进行排序

var orderedCount = function(text) {
  let splitted = text.split('');
  let countedLetters = splitted.reduce((AllLetters, letter) => {
    (letter in AllLetters) ? AllLetters[letter]++: AllLetters[letter] = 1;
    return AllLetters
  }, {})

  let result = Object.entries(countedLetters).sort((a, b) => {
    return b[1] - a[1];
  })

  return result
};
console.log(orderedCount("abracadabra")); 
console.log(orderedCount("212"));

---

较短的版本:

var orderedCount = function(text) {
  return Object.entries(text.split('').reduce((c, v) => {
    c[v] = (c[v] || 0) + 1;
    return c;
  }, {})).sort((a, b) => b[1] - a[1]);

};
console.log(orderedCount("abracadabra")); 
console.log(orderedCount("212"));