w3resource

JavaScript: Extract unique characters from a string

JavaScript Function: Exercise-16 with Solution

Write a JavaScript function to extract unique characters from a string.

Example string : "thequickbrownfoxjumpsoverthelazydog"
Expected Output : "thequickbrownfxjmpsvlazydg"

Sample Solution-1:

JavaScript Code:

// Define a function named unique_char that returns a string containing unique characters from the input string
function unique_char(str1) {
  // Create a variable str and initialize it with the input string
  var str = str1;

  // Create an empty string uniql to store unique characters
  var uniql = "";

  // Iterate through each character in the input string
  for (var x = 0; x < str.length; x++) {
    // Check if the current character is not already in the uniql string
    if (uniql.indexOf(str.charAt(x)) == -1) {
      // If true, append the current character to the uniql string
      uniql += str[x];
    }
  }

  // Return the string containing unique characters
  return uniql;
}

// Log the result of calling unique_char with the input string "thequickbrownfoxjumpsoverthelazydog" to the console
console.log(unique_char("thequickbrownfoxjumpsoverthelazydog")); 

Sample Output:

thequickbrownfxjmpsvlazydg

Flowchart:

Flowchart: JavaScript function: Extract unique characters from a strin

Live Demo:

See the Pen JavaScript - Extract unique characters from a string-function-ex- 16 by w3resource (@w3resource) on CodePen.


Sample Solution-2:

JavaScript Code:

// Function to extract unique characters from a string
function extractUniqueChars(inputString) {
    // Initialize an empty object to store unique characters
    const uniqueChars = {};

    // Iterate through each character in the input string
    for (let char of inputString) {
        // Add the character to the object as a key (objects cannot have duplicate keys)
        uniqueChars[char] = true;
    }

    // Join the keys of the object to form the result string of unique characters
    const resultString = Object.keys(uniqueChars).join('');

    return resultString;
}

// Example usage:
const inputString = "thequickbrownfoxjumpsoverthelazydog";
const result = extractUniqueChars(inputString);

// Log the result to the console
console.log(result);

Sample Output:

thequickbrownfxjmpsvlazydg

Flowchart:

Flowchart: JavaScript function: Extract unique characters from a strin

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript function to compute the value of bn where n is the exponent and b is the bases.
Next: Write a JavaScript function to get the number of occurrences of each letter in specified string.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.