Question

我想实现一个javascript程序，通过单词计算并返回单词及其出现的次数，例如{hello：2，“@ hello”：1，world：1，toString：1}

下面是我的代码，但我只得到了总字数

function words(str) { 
    app = {};
    return str.split(" ").length;
}

console.log(words("hello world"));

Answer 1

使用reduce来迭代单词数组，并计算实例：

function words(str) { 
    return str.split(" ").reduce(function(count, word) {
      count[word] = count.hasOwnProperty(word) ? count[word] + 1 : 1;
      
      return count;
    }, {});
}

console.log(words("reserved words like prototype and toString ok? Yes toString is fine"));

Answer 2

一种ES6方法，可以减少字符串等项目数组并返回计数：

const strFrequency = function (stringArr) {
  return stringArr.reduce((count, word) => {
        count[word] = (count[word] || 0) + 1;
        return count;
  }, {})
}

let names = ["Bob", "Bill", "Bo", "Ben", "Bob", "Brett", "Ben", "Bill", "Bo", "Ben", "Bob", "Ben"];

console.log(strFrequency(names));
// => {Bob: 3, Bill: 2, Bo: 2, Ben: 4, Brett: 1}

Answer 3

function words(str){


    var words = [];

    //check if words list is empty if so then insert the first word into the array


    if(!words.length){
        var word = str.split(" ")[0];
        words.push({"word":word, "occurences":1});
    }

    //convert string to array so you can iterate through it
    str = str.split(" ");

    //iterate through the array starting from the first position because word at the position 0 is already in the array
    for(var i = 1; i<str.length; i++){

        //iterate through the words list to the see if the word has appeared yet
        var wordExists = false;

        for(var j = 0; j<words.length; j++){
            if(str[i] == words[j].word){

                //word exists in word so count one up
                words[j].occurences += 1;

                //used to prevent the word from being inserted twice
                wordExists = true;
                break;
            }
        }

        //insert new word in words if it 
        if(!wordExists){
            words.push({"word":str[i], "occurences":1});
        }
    }
    return words;
}

Answer 4

这是代码以及我通过@ori

传递的内容

function words(str) { 
    var adjustedStr = str.replace(/\n|\t|\s\s+/g, ' ');
    return adjustedStr.split(' ').reduce(function(count, word) {
    count[word] = (count[word] || 0) + 1;

    return count;
    }, {});
}

console.log(words("reserved words like prototype and toString ok?"));

它安慰了

{toString: "function toString() { [native code] }1"}

Answer 5

要在不使用hasOwnerProperty的情况下允许对象文字中的保留字，可以对Object使用null构造函数。

例如

＆＃13;

function words(str) { 
    var adjustedStr = str.replace(/\n|\t|\s\s+/g, ' ');
    return adjustedStr.split(' ').reduce(function(count, word) {
      count[word] = (count[word] || 0) + 1;
      return count;
    }, Object.create(null));
}

console.log(words("reserved words like prototype and toString ok?"));

＆＃13;

计算javascript中的单词并将其推入对象

5 个答案: