--- id: a6e40f1041b06c996f7b2406 title: Finders Keepers isRequired: true challengeType: 5 videoUrl: '' localeTitle: Finders Keepers --- ## Description <section id="description">创建一个查看数组(第一个参数)的函数,并返回数组中传递真值测试的第一个元素(第二个参数)。如果没有元素通过测试,则返回undefined。如果卡住,请记得使用<a href="http://forum.freecodecamp.org/t/how-to-get-help-when-you-are-stuck/19514" target="_blank">Read-Search-Ask</a> 。尝试配对程序。编写自己的代码。 </section> ## Instructions <section id="instructions"> </section> ## Tests <section id='tests'> ```yml tests: - text: '<code>findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</code>应该返回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>应返回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.");' ``` </section> ## Challenge Seed <section id='challengeSeed'> <div id='js-seed'> ```js function findElement(arr, func) { let num = 0; return num; } findElement([1, 2, 3, 4], num => num % 2 === 0); ``` </div> </section> ## Solution <section id='solution'> ```js // solution required ``` </section>