freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/finders-keepers.english.md

id	title	isRequired	challengeType
a6e40f1041b06c996f7b2406	Finders Keepers	true	5

Description

Create a function that looks through an array (first argument) and returns the first element in the array that passes a truth test (second argument). If no element passes the test, return undefined. Remember to use Read-Search-Ask if you get stuck. Try to pair program. Write your own code.

Instructions

Tests

tests:
  - text: <code>findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</code> should return 8.
    testString: assert.strictEqual(findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; }), 8, '<code>findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</code> should return 8.');
  - text: <code>findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; })</code> should return undefined.
    testString: assert.strictEqual(findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; }), undefined, '<code>findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; })</code> should return undefined.');

Challenge Seed

function findElement(arr, func) {
  let num = 0;
  return num;
}

findElement([1, 2, 3, 4], num => num % 2 === 0);

Solution

function findElement(arr, func) {
  return arr.filter(func)[0];
}

findElement([1, 2, 3, 4], num => num % 2 === 0);