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

id, title, challengeType, forumTopicId

id	title	challengeType	forumTopicId
a6e40f1041b06c996f7b2406	Finders Keepers	5	16016

Description

Create a function that looks through an array arr and returns the first element in it that passes a 'truth test'. This means that given an element x, the 'truth test' is passed if func(x) is true. If no element passes the test, return undefined.

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);
  - 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);

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);