find_occurances.js

const findTotalOccurancesEachCharInAString = (str) => {
  let charMap = {};
  let merge = "";

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

  for (let char in charMap) {
    merge += char + charMap[char];
  }

  return merge;
};

const findTotalOccurancesEachCharInAStringV2 = (str) => {
  let charMap = {};

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

  return Object.keys(charMap)
    .filter((res) => charMap[res] > 1)
    .join("");
};

const findTotalOccurancesEachCharInAStringV3 = (str) => {
  let charMap = {};

  str.split("").forEach((char) => {
    charMap[char] = (charMap[char] || 0) + 1;
  });

  return Object.keys(charMap)
    .filter((res) => charMap[res] > 1)
    .join("");
};

export {
  findTotalOccurancesEachCharInAString,
  findTotalOccurancesEachCharInAStringV2,
  findTotalOccurancesEachCharInAStringV3,
};