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freeCodeCamp/curriculum/challenges/chinese-traditional/02-javascript-algorithms-and-data-structures/functional-programming/use-the-every-method-to-check-that-every-element-in-an-array-meets-a-criteria.md
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---
id: 587d7dab367417b2b2512b6e
title: 使用 every 方法檢查數組中的每個元素是否符合條件
challengeType: 1
forumTopicId: 301312
dashedName: use-the-every-method-to-check-that-every-element-in-an-array-meets-a-criteria
---
# --description--
`every` 方法用於檢測數組中*所有*元素是否都符合指定條件。 如果所有元素滿足條件,返回布爾值 `true`,反之返回 `false`
舉個例子,下面的代碼檢測數組 `numbers` 的所有元素是否都小於 10
```js
const numbers = [1, 5, 8, 0, 10, 11];
numbers.every(function(currentValue) {
return currentValue < 10;
});
```
`every` 方法在這裏會返回 `false`
# --instructions--
`checkPositive` 函數中使用 `every` 方法檢查 `arr` 中是否所有元素都是正數。 函數應返回一個布爾值。
# --hints--
應使用`every`方法。
```js
assert(code.match(/\.every/g));
```
`checkPositive([1, 2, 3, -4, 5])` 應返回 `false`
```js
assert.isFalse(checkPositive([1, 2, 3, -4, 5]));
```
`checkPositive([1, 2, 3, 4, 5])` 應返回 `true`
```js
assert.isTrue(checkPositive([1, 2, 3, 4, 5]));
```
`checkPositive([1, -2, 3, -4, 5])` 應返回 `false`
```js
assert.isFalse(checkPositive([1, -2, 3, -4, 5]));
```
# --seed--
## --seed-contents--
```js
function checkPositive(arr) {
// Only change code below this line
// Only change code above this line
}
checkPositive([1, 2, 3, -4, 5]);
```
# --solutions--
```js
function checkPositive(arr) {
return arr.every(num => num > 0);
}
```