JAVASCRIPT

JavaScript find repeated character

Input:
S = "geeksforgeeks"
Output: g
Explanation: g, e, k and s are the repeating
characters. Out of these, g occurs first.


const repeatedCharacter = (str) => {
  for (let i = 0; i < str.length - 1; i++) {
    for (let j = i + 1; j < str.length; j++) {
      if (str[i] === str[j]) {
        return str[i];
      }
    }
  }
  return -1
};
console.log(repeatedCharacter("geeksforgeeks"));

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"]

javascript check repeated char

function hasRepeats (str) {
    return /(.).*1/.test(str);
}

duplicate characters in a string javascript

const text = 'abcda'.split('')
text.some( (v, i, a) => {
  return a.lastIndexOf(v) !== i
}) // true