Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

JavaScript: Remove all characters from a given string that appear more than once

JavaScript Basic: Exercise-135 with Solution

Write a JavaScript program to remove all characters from a given string that appear more than once.

Pictorial Presentation:

JavaScript: Remove all characters from a given string that appear more than once.

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Remove all characters from a given string that appear more than once</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function remove_duplicate_cchars(str) {
  var arr_char = str.split("");
  var result_arr = [];

  for (var i = 0; i < arr_char.length; i++) {
    if (str.indexOf(arr_char[i]) === str.lastIndexOf(arr_char[i]))
      result_arr.push(arr_char[i]);
    }

  return result_arr.join("");
}
console.log(remove_duplicate_cchars("abcdabc"));
console.log(remove_duplicate_cchars("python"));
console.log(remove_duplicate_cchars("abcabc"));
console.log(remove_duplicate_cchars("1365451"));

Sample Output:

d
python

364

Flowchart:

Flowchart: JavaScript - Remove all characters from a given string that appear more than once

ES6 Version:

function remove_duplicate_cchars(str) {
  const arr_char = str.split("");
  const result_arr = [];

  for (let i = 0; i < arr_char.length; i++) {
    if (str.indexOf(arr_char[i]) === str.lastIndexOf(arr_char[i]))
      result_arr.push(arr_char[i]);
    }

  return result_arr.join("");
}
console.log(remove_duplicate_cchars("abcdabc"));
console.log(remove_duplicate_cchars("python"));
console.log(remove_duplicate_cchars("abcabc"));
console.log(remove_duplicate_cchars("1365451"));

Live Demo:

See the Pen javascript-basic-exercise-135 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to change the characters (lower case) in a string where a turns into z, b turns into y, c turns into x, ..., n turns into m, m turns into n, ..., z turns into a.
Next: Write a JavaScript program to replace the first digit in a string (should contains at least digit) with $ character.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04