ES6: Write Higher Order Arrow Functions

ES6: Write Higher Order Arrow Functions


I am reading but this just is not making sense to me… I am getting the filtered numbers… but the squaring part of the function just does not seem to magically appear through the fog…
Here is my latest code :

const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34];
const squareList = (arr) => {
  "use strict";
  // change code below this line
let squaredIntegers =realNumberArray.filter(num)=>(num%2===0&&num>0);>num*num);

  // change code above this line
  return squaredIntegers;
// test your code
const squaredIntegers = squareList(realNumberArray);

#teachmelikeImFive LOL…

Thank you in advance for your kind consideration…


Hello, @BrBearOFS. You’ve almost made it. Just a few changes:

  1. Check quotes symbols (line 3) and change them to proper once ’ … ’ or ‘’ … "
  2. Your filter statement should be put in () like so:
  3. While using map make sure that you assign your logic to each array element:
    .map((num)=>num = num* num)

If you make these slight changes your code will work and you’ll see magic happening :slightly_smiling_face:


I’ve edited your post for readability. When you enter a code block into the forum, precede it with a line of three backticks and follow it with a line of three backticks to make easier to read. See this post to find the backtick on your keyboard. The “preformatted text” tool in the editor (</>) will also add backticks around text.


Two of these are bad advice

The type of quotation marks do not matter

Using (num) => num = num * num is pointless, though it happens to give you the right answer also, (num) => num * num is idiomatic


I see what you’re trying to do with your filter function, but you’ll find it easier to filter usingNumber.isInteger

Once filter has its argument sorted you’re basically done, nice work


You can map the filter itself

let squaredIntegers = realNumberArray.filter(num)=>(num%2===0&&num>0).map((x)x*x);



THank you for the point in the direction… once I added the additional parenthesis, it passed and I was busy kicking myself for not seeing it… …

I appreciate the time and response.




Thank you for your response… I do have a question…

in the .map((x)xx) ; portion… is there no operator of some sort necessary ?
like the .map ((x)+>x
x) ?

Thank you again…


Thank you Ariel …

I will endeavor not to be THAT guy LOL…


THank you Gebulmer,

I did see the IsInteger () on I think it was stackflow… there was some reason it was bumped down because of something to do with its methodology or interpolation… I will have to go back and look again…
however, yes ! it would clear some of the typing… :slight_smile:

Thank you for your time and response…


My b man, you’re right. I overlooked my code. Its a transformation of the filter so yeah.

let squaredIntegers = realNumberArray.filter((num)=>num%2===0&&num>0).map((x)=>x*x);