Answers for "how to calculate most repeated characater in a string in js"

how to find repeated characters in a string in javascript

/* Time complexity of solution: O(n) */
const getRepeatedChars = (str) => {
 	const chars = {};
    for (const char of str) {
        chars[char] = (chars[char] || 0) + 1;
    }
    return Object.entries(chars).filter(char => char[1] > 1).map(char => char[0]);
}

getRepeatedChars("aabbkdndiccoekdczufnrz"); // ["a", "b", "c", "d", "k", "n", "z"]

first repeated character in a string javascript

function firstRepeatingCharacter(str) {
  for (let i = 0; i < str.length; i++) {
    if (str.indexOf(str.charAt(i)) !== str.lastIndexOf(str.charAt(i))) {
      return str.charAt(i)
    }
  }
  return 'no results found'
}