前端--js基础（哈希表的应用）

编写一个函数查找一篇英文文章中出现频率最高的单词(由26个英文字母大小写构成)，输出该单词及出现次数，不区分大小写，主要是正则和哈希表的运用

// 这种方法应该是查找出现频率最高的字母
function searchWord1(article){
    if(!article)return;
    // 参数处理，清除除了单词间空格外的文本中的所有空格，并转换所有字母为小写
    article = article.trim().toLowerCase();
    // 按照正则做单词的全局匹配 输出文章中的所有单词得到一个都是单词字符的数组
    let wordList = article.match(/[a-z]+/g);
    // 存储搜索过的单词
    let visited = [];
    // 单词的出现次数
    let maxNum = 0;
    // 出现频率最高的那个单词
    let maxWord = '';
    // 把数组还原成字符串形式
    article = "" + wordList.join(" ")+"";
    wordList.forEach((item)=>{
        if(visited.indexOf(item) === -1){
            visited.push(item);
            // 新建正则对象
            let word = new RegExp(""+item+"","g");
            let num = article.match(word).length;
            if(num>maxNum){
                maxNum = num;
                maxWord = item;
            }
        }
    })
    return maxWord + "  " + maxNum;
}

// 另一种做法
function searchWord(article) {
    if (!article) return;
    // 基本处理
    article = article.trim().toLowerCase();
    // 正则切分成数组便于循环
    let wordList = article.match(/[a-z]+/g);
    console.log(wordList);
    let maxWord = '';
    let maxNum = 1;
    let visited = {};
    // 把文章切分成一个个字母空格的形式
    // article = ""+wordList.join(" ")+"";
    for (let i = 0; i < wordList.length; i++) {
        if (visited[wordList[i]]) {
            visited[wordList[i]]++;
            if (visited[wordList[i]] > maxNum) {
                maxNum = visited[wordList[i]];
                maxWord = wordList[i];
            }
        } else {
            visited[wordList[i]]=1;
        }
    }
    return maxNum + " " + maxWord
}
console.log(searchWord('Each human being is born as something new, something that never existed before. Each is born with the capacity to win at life. Each person has a unique way of seeing, hearing, touching, tasting and thinking. Each has his or her own unique potentials---capabilities and limitations. Each can be a significant, thinking, aware, and creative being---a productive person, a winner.'))