30 lines
856 B
Markdown
30 lines
856 B
Markdown
|
---
|
|||
|
|
title: Copy Array Items Using slice()
|
|||
|
|
localeTitle: 使用slice（）复制数组项
|
|||
|
|
---
|
|||
|
|
## 使用slice（）复制数组项
|
|||
|
|
|
|||
|
|
* `slice()`函数必须用于返回仅包含`warm` `sunny`的数组。
|
|||
|
|
* 因此，必须将两个参数传递给`slice()`函数。第一个参数必须是您希望子字符串开始的索引。第二个参数必须是子字符串结束的索引。
|
|||
|
|
* 注意：第二个参数将在该精确索引处结束子字符串。
|
|||
|
|
|
|||
|
|
## 例：
|
|||
|
|
|
|||
|
|
```javascript
|
|||
|
|
return arr.slice(1,4);
|
|||
|
|
/* This will return a substring consisting of indexs [1,2,3]
|
|||
|
|
Note: arr[4] is NOT included.
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
## 解：
|
|||
|
|
|
|||
|
|
```javascript
|
|||
|
|
function forecast(arr) {
|
|||
|
|
// change code below this line
|
|||
|
|
return arr.slice(2,4);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// do not change code below this line
|
|||
|
|
console.log(forecast(['cold', 'rainy', 'warm', 'sunny', 'cool', 'thunderstorms']));
|
|||
|
|
|
|||
|
|
```
|