javascript 查找字符串中出现频率最高的字符javascript

Finding the most frequent character in a string javascript

提问by N4pster

Assuming I have the following string "355385". I need a simple JavaScript that can tell me that the most mentioned character is 5. Thank you in advance.

假设我有以下字符串“35538​​5”。我需要一个简单的 JavaScript 来告诉我提到最多的字符是 5。提前谢谢你。

I tried with this one but no results.

我试过这个，但没有结果。

var exp = '355385' ;

var exps =exp.split("");

var expCounts = { };

for (var i=0;i<exp.length;i++)

{expCounts["_" + exps[i]] = (expCounts["_" + exps[i]] || 0) + 1 ;

if (expCounts==3) exps=exps[i]; }; exps;

回答by row1

This will loop over every character in the string and keep track of each character's count and the character with the maximum count:

这将遍历字符串中的每个字符并跟踪每个字符的计数和具有最大计数的字符：

var exp = '3553853335' ;
var expCounts = {};
var maxKey = '';
for(var i = 0; i < exp.length; i++)
{
    var key = exp[i];
    if(!expCounts[key]){
     expCounts[key] = 0;
    }
    expCounts[key]++;
    if(maxKey == '' || expCounts[key] > expCounts[maxKey]){
        maxKey = key;
    }
}

console.debug(maxKey + ":" + expCounts[maxKey]);

---

---

Update:Here is an ES6 version that will handle strings where multiple character have the same max count

更新：这是一个 ES6 版本，它将处理多个字符具有相同最大计数的字符串

function maxCount(input) {
    const {max, ...counts} = (input || "").split("").reduce(
    (a, c) => {
        a[c] = a[c] ? a[c] + 1 : 1;
        a.max = a.max < a[c] ? a[c] : a.max;
        return a;
    },
    { max: 0 }
    );

    return Object.entries(counts).filter(([k, v]) => v === max);
}

Example (please excuse the crude output):

示例（请原谅粗输出）：

maxCount('--aaaa1111--').join(' | ').replace(/,/g, ':');

outputs 1:4 | -:4 | a:4

输出 1:4 | -:4 | a:4

回答by Sarath

var getMax = function (str) {
 var max = 0,
     maxChar = '';
  str.split('').forEach(function(char){
    if(str.split(char).length > max) {
        max = str.split(char).length;
        maxChar = char;
     }
  });
  return maxChar;
};

logs

日志

getMax('355385') //5;

getMax('35538533') //3;

in equal case it will return first number

在同等情况下，它将返回第一个数字

getMax('3553') //3;

回答by thefourtheye

var string  = "355385",
    counter = {};

for (var i = 0, len = string.length; i < len; i += 1) {
    counter[string[i]] = (counter[string[i]] || 0) + 1;
}

var biggest = -1, number;
for (var key in counter) {
    if (counter[key] > biggest) {
        biggest = counter[key];
        number = key;
    }
}

console.log(number);
# 5

回答by brutallord

var exp = '355385';
var findMostFrequent = function (string) {
    var chars = {}, first = string.charAt(0);
    chars[first] = 1;
    var maxChar = first, maxCount = 1;

    for (var i = 1; i < string.length; i++) {
        var char = string.charAt(i);
        if (chars[char]) {
            chars[char]++;
        } else {
            chars[char] = 1;
        }
        if (chars[char] > maxCount) {
            maxChar = char;
        }
    }
    return maxChar;
};

回答by HappyHands31

Another way to get the most frequent character in a string - sort frequency map into an array and then return the first (greatest) value from that array:

另一种获取字符串中出现频率最高的字符的方法 - 将频率映射排序到一个数组中，然后从该数组中返回第一个（最大）值：

function highest (string) {
  let array = Array.from(string);
  let frequencyMap = {};
  array.forEach((value, index) => {
    if (!frequencyMap[value]) {
      frequencyMap[value] = 0;
    }
    frequencyMap[value] += 1;
  })
  let frequencyArray = Object.entries(frequencyMap);
  frequencyArray.sort((a, b) => {
    if (a[1] < b[1]) {
      return 1;
      }
    if (a[1] > b[1]) {
      return -1;
      }
      return 0;
    });
  return(frequencyArray[0][0]);
}

console.log(highest("hello World"));

returns "l"

返回“l”

回答by bajran

Another Solution

另一种解决方案

function maxChar(str) {

        const charMap = {};
        let max = 0;
        let maxChar = '';

        for(let char of str){
            if(charMap[char]){
                charMap[char]++;
            }else{
                charMap[char] = 1;
            }
        }

        for(let char in charMap){
            if(charMap[char] > max){
                max = charMap[char];
                maxChar = char;
            }
        }

        return maxChar; 
}

Result:

结果：

 maxChar('355385') 
  "5"

回答by Angyal Norbert

You can use the following solution to find the most frequent character in a string:

您可以使用以下解决方案来查找字符串中出现频率最高的字符：

function getMostRepeatedCharacter(string) {
    return string.split('').reduce((acc,char)=>{
        let len = string.split(char).length - 1;
        return len > acc[1] ? [char,len] : acc
    },['',0])[0]
}

getMostRepeatedCharacter('wediuaududddd') // d

回答by Sumer

Want to share this ES6 functional approach. Please provide your input.

想分享这个 ES6 函数式方法。请提供您的意见。

function maxChar(myStr) {
  let charObj = {};
  return [...myStr].reduce((_, char) => {
    if (char in charObj) charObj[char]++;
    else if (char !== " ") charObj[char] = 1;
    return Object.keys(charObj).reduce((a, b) => {
      return charObj[a] > charObj[b] ? a : b;
    });
  });
}

回答by Andrii Gordiichuk

Here is:

这是：

let str = '355385';
function mostFrequentCharacter(str) {
        let charactersArr = str.split(''),
            bins = {};

        charactersArr.map(el => bins[el] = (bins[el] || 0) + 1); 
    return Object.keys(bins).map(key => ({
            name: key,
          count: bins[key]
    })).sort((a, b) => b.count - a.count)[0];
}

回答by Alisher Musurmonv

function solution(N) {
    var textToArr = N.split('');
    var newObj = {};
    var newArr = [];

    textToArr.map((letter) => {
        if(letter in newObj){
            newObj[letter] = newObj[letter]+1;
        } else {
            if(letter !== ' '){
               newObj = Object.assign(newObj, {[letter]: 1})
            }
        }
    });

    for(let i in newObj){
        newArr.push({name: i, value: newObj[i]})
    }

    var res = newArr.sort((a,b) => b.value-a.value)[0];
    return res.name+':'+res.value
}

solution("hello world");