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.

Visual Presentation:

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

Sample Solution:

JavaScript Code:

/**
 * Function to remove duplicate characters from a string
 * @param {string} str - The input string
 * @returns {string} - The string without duplicate characters
 */
function remove_duplicate_chars(str) {
  // Split the string into an array of characters
  var arr_char = str.split("");
  var result_arr = [];

  // Loop through each character of the array
  for (var i = 0; i < arr_char.length; i++) {
    // Check if the first and last occurrence of a character in the string are the same
    if (str.indexOf(arr_char[i]) === str.lastIndexOf(arr_char[i]))
      result_arr.push(arr_char[i]);
  }

  // Join the array of unique characters and return as a string
  return result_arr.join("");
}

console.log(remove_duplicate_chars("abcdabc"));
console.log(remove_duplicate_chars("python"));
console.log(remove_duplicate_chars("abcabc"));
console.log(remove_duplicate_chars("1365451"));

Output:

d
python

364

Live Demo:

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

Flowchart:

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

ES6 Version:

/**
 * Function to remove duplicate characters from a string
 * @param {string} str - The input string
 * @returns {string} - The string without duplicate characters
 */
const remove_duplicate_chars = (str) => {
  // Split the string into an array of characters
  const arr_char = str.split("");
  const result_arr = [];

  // Loop through each character of the array
  for (let i = 0; i < arr_char.length; i++) {
    // Check if the first and last occurrence of a character in the string are the same
    if (str.indexOf(arr_char[i]) === str.lastIndexOf(arr_char[i]))
      result_arr.push(arr_char[i]);
  }

  // Join the array of unique characters and return as a string
  return result_arr.join("");
}

console.log(remove_duplicate_chars("abcdabc"));
console.log(remove_duplicate_chars("python"));
console.log(remove_duplicate_chars("abcabc"));
console.log(remove_duplicate_chars("1365451"));

Improve this sample solution and post your code through Disqus.

Previous: 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: 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.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://w3resource.com/javascript-exercises/javascript-basic-exercise-135.php