我真的被这个递归函数问题困住了，我需要返回对象中计数最多的元音

Question

const VOWELS = ['a', 'e', 'i', 'o', 'u'];

const mostFrequentVowel = function (words, counter = {}) {
    let count = 0
    if (words.length === 0) {
        return ''
    }
    let lastString = words[words.length - 1]
    for (let i = 0; i < lastString.length; i++) {
        const letter = lastString[i];
        if (VOWELS.includes(letter)) {
            count++
            if (letter in counter) {
                counter[letter] += 1
            } else {
                counter[letter] = 1
            }
        }
    }
    let values = Object.values(counter)
    let max = Math.max(...values)
    for (let vowel in counter) {
        if (counter[vowel] === max) {
            return vowel
        }
    }
    return mostFrequentVowel(words.slice(0, words.length - 1), counter)

}
console.log(mostFrequentVowel(['dog', 'cow', 'pig', 'chicken', 'horse'])); // 'o'
mostFrequentVowel(['dog', 'cow', 'pig', 'chicken']); // 'i' or 'o'

我无法更新计数器对象以反映最大的元音。我想知道这是否是 for in 循环接近尾声的问题，或者它是否在第一个 for 循环中存在一些逻辑。

Answer 1

改用这个：

const VOWELS = ['a', 'e', 'i', 'o', 'u'];

function mostFrequentVowel(inputs)
{
  var max=0;
  VOWELS.forEach(p=>max=Math.max(inputs.join().match(new RegExp(p, 'gm'))?.length ?? 0,max));
  return VOWELS[max]; // <-Update | mistake -> inputs[max];
}

Answer 2

'use strict'

const mostFrequentVowel = function (words) {
    if (words.length === 0) {
        return null
    }
    const vowels = ['a', 'e', 'i', 'o', 'u'];
    let vowelsCounter = {
        'a': 0, 
        'e': 0, 
        'i': 0, 
        'o': 0, 
        'u': 0
    };

    const allWords = words.join('')
    console.log(`allWords: ${allWords}`) // allWords: dogcowpigchickenhorse
     
    const chars = allWords.split('');
    console.log(`chars: ${chars}`) // chars: d,o,g,c,o,w,p,i,g,c,h,i,c,k,e,n,h,o,r,s,e
     
    const allVowels = chars.filter(letter => vowels.includes(letter))
    console.log(`allVowels: ${allVowels}`) // allVowels: o,o,i,i,e,o,e

    const vowelsCounterFinal = allVowels.reduce( (acc, vowel) => { // acc ==> acumulator (the previous state) // currentOrder ==> current value in the loop
        acc[vowel] = acc[vowel] + 1
        return acc // REDUCER ==> Remembers the previous state // return the next state 
    },
        vowelsCounter // DEFAULT TO START WITH
    )

    console.log(`vowelsCounterFinal: ${vowelsCounterFinal}`)
 
    const keyWithTheHighestValueFromObject = Object.keys(vowelsCounterFinal).reduce((a, b) => vowelsCounterFinal[a] > vowelsCounterFinal[b] ? a : b);
    // return keyWithTheHighestValueFromObject // return only the vowel
    return { 
        vowel: keyWithTheHighestValueFromObject,
        count: vowelsCounter[keyWithTheHighestValueFromObject] 
    }  // return the vowel and the count
    console.log('Debigging')
}

const wordsArray = ['dog', 'cow', 'pig', 'chicken', 'horse']

console.log(JSON.stringify(mostFrequentVowel(wordsArray), null, 2))

/*
{
  "vowel": "o",
  "count": 3
}
*/

Answer 3

你必须使用递归吗？？？ 如果没有：

const VOWELS = ['a', 'e', 'i', 'o', 'u'];

const mostFrequentVowel = function (words) {
    const vowelCount = words.reduce((accumulator, word) => {
        Array.from(word).forEach(character => {
            if (VOWELS.includes(character)) {
                accumulator = { ...accumulator, [character]: accumulator[character] ? accumulator[character] + 1 : 1 }
            }
        })
        return accumulator
    }, {})
    return Object.keys(vowelCount).reduce((a, b) => vowelCount[a] > vowelCount[b] ? a : b)

}
console.log(mostFrequentVowel(['dog', 'cow', 'pig', 'chicken', 'horse'])); // 'o'
console.log(mostFrequentVowel(['dog', 'cow', 'pig', 'chicken'])); // 'i' or 'o'

Answer 4

问题是只有当单词长度=== 1（列表中剩余的最后一个单词）时才应该调用第一个返回。 代码的编写方式，只要有元音，就会调用第一个返回。这个 if 语句可以解决这个问题：

const mostFrequentVowel = function (words, counter = {}) {
    let count = 0
    if (words.length === 0) {
        return ''
    }
    let lastString = words[words.length - 1]
    for (let i = 0; i < lastString.length; i++) {
        const letter = lastString[i];
        if (VOWELS.includes(letter)) {
            count++
            if (letter in counter) {
                counter[letter] += 1
            } else {
                counter[letter] = 1
            }
        }
    }

    if (words.length === 1) {
        let values = Object.values(counter)
        let max = Math.max(...values)
        for (let vowel in counter) {
            if (counter[vowel] === max) {
                return vowel
            }
        }
    }
    else {
        return mostFrequentVowel(words.slice(0, words.length - 1), counter);
    };
};

希望这个答案对您的问题有所帮助