Finding The Most Frequent Character In A String Javascript

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. I tried with this one but n

Solution 1:

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

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

functionmaxCount(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 }
    );

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

Example (please excuse the crude output):

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

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

Solution 2:

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

getMax('355385') //5;getMax('35538533') //3;

in equal case it will return first number

getMax('3553') //3;

Solution 3:

varstring  = "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

Solution 4:

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

Solution 5:

Another Solution

function maxChar(str) {

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

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

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

        return maxChar; 
}

Result:

 maxChar('355385') 
  "5"