80 lines
1.9 KiB
Markdown
80 lines
1.9 KiB
Markdown
---
|
||
id: 587d7dab367417b2b2512b6e
|
||
challengeType: 1
|
||
forumTopicId: 301312
|
||
localeTitle: 使用 every 方法检查数组中的每个元素是否符合条件
|
||
---
|
||
|
||
## Description
|
||
<section id='description'>
|
||
<code>every</code>方法用于检测数组中<em>所有</em>元素是否都符合指定条件。如果所有元素满足条件，返回布尔值<code>true</code>，反之返回<code>false</code>。
|
||
举个例子，下面的代码检测数组<code>numbers</code>的所有元素是否都小于 10：
|
||
|
||
```js
|
||
var numbers = [1, 5, 8, 0, 10, 11];
|
||
numbers.every(function(currentValue) {
|
||
return currentValue < 10;
|
||
});
|
||
// Returns false
|
||
```
|
||
|
||
</section>
|
||
|
||
## Instructions
|
||
<section id='instructions'>
|
||
在<code>checkPositive</code>函数中使用<code>every</code>方法检查<code>arr</code>中是否所有元素都是正数，函数应返回一个布尔值。
|
||
</section>
|
||
|
||
## Tests
|
||
<section id='tests'>
|
||
|
||
```yml
|
||
tests:
|
||
- text: 应使用<code>every</code>方法。
|
||
testString: assert(code.match(/\.every/g));
|
||
- text: <code>checkPositive([1, 2, 3, -4, 5])</code>应返回<code>false</code>。
|
||
testString: assert.isFalse(checkPositive([1, 2, 3, -4, 5]));
|
||
- text: <code>checkPositive([1, 2, 3, 4, 5])</code>应返回<code>true</code>。
|
||
testString: assert.isTrue(checkPositive([1, 2, 3, 4, 5]));
|
||
- text: <code>checkPositive([1, -2, 3, -4, 5])</code>应返回<code>false</code>。
|
||
testString: assert.isFalse(checkPositive([1, -2, 3, -4, 5]));
|
||
|
||
```
|
||
|
||
</section>
|
||
|
||
## Challenge Seed
|
||
<section id='challengeSeed'>
|
||
|
||
<div id='js-seed'>
|
||
|
||
```js
|
||
function checkPositive(arr) {
|
||
// Add your code below this line
|
||
|
||
|
||
// Add your code above this line
|
||
}
|
||
checkPositive([1, 2, 3, -4, 5]);
|
||
```
|
||
|
||
</div>
|
||
|
||
|
||
|
||
</section>
|
||
|
||
## Solution
|
||
<section id='solution'>
|
||
|
||
```js
|
||
function checkPositive(arr) {
|
||
// Add your code below this line
|
||
return arr.every(num => num > 0);
|
||
// Add your code above this line
|
||
}
|
||
checkPositive([1, 2, 3, -4, 5]);
|
||
```
|
||
|
||
</section>
|