freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/es6/write-higher-order-arrow-functions/index.md

title
Write Higher Order Arrow Functions

Remember to use Read-Search-Ask if you get stuck. Try to pair program and write your own code

Problem Explanation:

We need to compute and square values from the realNumberArray and store them in the variable squaredIntegers using the map(), filter(), and/or reduce() functions.

Hint: 1

• You will need to filter() the realNumberArray for positive integers (decimals are not integers).

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Hint: 2

• You will need to map() the values from your filter() function to the variable squaredIntegers.

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Hint: 3

• Remember the magic of chaining functions.

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Spoiler Alert!

Solution ahead!

Basic Code Solution:

    const squareList = (arr) => {
      "use strict";
      const squaredIntegers = arr.filter( (num) => num > 0 && num % parseInt(num) === 0 ).map( (num) => Math.pow(num, 2) );
      return squaredIntegers;
    };

    // test your code
    const squaredIntegers = squareList(realNumberArray);
    console.log(squaredIntegers);

Run Code

Code Explanation:

Uses the operator filter() and map() functions to square all positive integers in a given array.

Relevant Links

• map()
• filter()
• reduce()

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