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What’s your alternative solution? Challenge #29

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About this series

This is series of daily JavaScript coding challenges... for both beginners and advanced users.

Each day I’m gone present you a very simple coding challenge, together with the solution. The solution is intentionally written in a didactic way using classic JavaScript syntax in order to be accessible to coders of all levels.

Solutions are designed with increase level of complexity.

Today’s coding challenge

Create a function that will receive an array of numbers as argument and will return a new array with distinct elements

(scroll down for solution)

Code newbies

If you are a code newbie, try to work on the solution on your own. After you finish it, or if you need help, please consult the provided solution.

Advanced developers

Please provide alternative solutions in the comments below.

You can solve it using functional concepts or solve it using a different algorithm... or just solve it using the latest ES innovations.

By providing a new solution you can show code newbies different ways to solve the same problem.


// Solution for challenge27a

var ar = getDistinctElements([1, 2, 3, 6, -1, 2, 9, 7, 10, -1, 100]);

function getDistinctElements(ar)
    var ar2 = [];

    for(let i = 0; i < ar.length; i++)
        if (!isInArray(ar[i], ar2))

    return ar2;

function isInArray(n, ar)
    for(let i = 0; i < ar.length; i++)
        if (ar[i] === n)
            return true;

    return false;

To quickly verify this solution, copy the code above in this coding editor and press "Run".

Note: The solution was originally designed for environment, and therefore is making use of println. This is the almost equivalent of console.log in other environments. Please feel free to use your preferred coding playground / environment when implementing your solution.

Discussion (2)

themobiledev profile image
Chris McKay • Edited

So, here's my solution:

var ar = getDistinctElements([1, 2, 3, 6, -1, 2, 9, 7, 10, -1, 100]);
function getDistinctElements(ar = []) {
    return [ Set(ar)];

So, just by way of explanation, Set is an object that only accepts distinct values. Using the spread operator (...) inside array brackets converts the set back into an array.

tomsfernandez profile image
Tomas Fernandez

With a reduce

function distinct(list = []){
  const reduced = list.reduce((acc, curr) => {
    acc[curr] = curr;
    return acc;
  }, {})
  return Object.values(reduced)