Write Higher Order Arrow Functions -FCC

JavaScript
1

Tell us what’s happening:
I have ended up here solving this, can anyone help me, please?

My code so far


const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34];
const squareList = (arr) => {
  "use strict";
  // change code below this line
  const squaredIntegers = arr.filter((arr) => arr > 0);
  // change code above this line
  return squaredIntegers;
};
// test your code
const squaredIntegers = squareList(realNumberArray);
console.log(squaredIntegers);

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Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/es6/write-higher-order-arrow-functions/

2

Hey Guys, I got the solution. Use Number.isInteger() method to filter out the integers, here is the solution

const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34];
const squareList = (arr) => {
“use strict”;
// change code below this line
const squaredIntegers = arr.filter((num) => num > 0 && Number.isInteger(num)).map((num)=> num*num);
// change code above this line
return squaredIntegers;
};
// test your code
const squaredIntegers = squareList(realNumberArray);
console.log(squaredIntegers);

3

You’ll get better answers if you post any error messages you get, but anyway - you’ve used the variable name arr both on the name of the array you’re filtering as well as within the callback itself. Try changing it to something like arr.filter(a => a > 0)

4

Thank you James :slightly_smiling_face:

5

close to what I got.

const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34];
const squareList = (arr) => {
  "use strict";
  // change code below this line
  const squaredIntegers = arr.filter( (num) => num > 0 && num % Number.isInteger(num) === 0).map((num) => num * num);
  // change code above this line
  return squaredIntegers;
};
// test your code
const squaredIntegers = squareList(realNumberArray);
console.log(squaredIntegers);

my test would not pass without adding the " Number.isInteger(num) === 0

6

Just to clarify. Number.isInteger() returns a boolean, so:

num % Number.isInteger(num) === 0

translates to: give me the remainder of num divided by boolean equals to 0.

For example, in the first item of the array (4), you’re doing this: return the element with a value of 4 if 4 % Number.isInteger(4) === 0 -> 4 % true === 0 -> 4 % 1 === 0 -> 0 === 0 -> true. In other words, if the value is an integer, it will always be returned.

Having said that, the code you wrote is equivalent to Number.isInteger(num).