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:

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:

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?
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JavaScript: Tips of the Day
Returns the sum of the powers of all the numbers from start to end (both inclusive)
Example:
const sumPower = (end, power = 2, start = 1) => Array(end + 1 - start) .fill(0) .map((x, i) => (i + start) ** power) .reduce((a, b) => a + b, 0); console.log(sumPower(10)); // 385 console.log(sumPower(10, 3)); // 3025 console.log(sumPower(10, 3, 5)); // 2925
Output:
385 3025 2925
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