---
id: bd7123c9c450eddfaeb5bdef
title: Use Bracket Notation to Find the Nth Character in a String
challengeType: 1
videoUrl: ''
localeTitle: 使用括号表示法查找字符串中的第N个字符
---
## Description
您还可以使用括号表示法来获取字符串中其他位置的字符。请记住，计算机从0开始计数，因此第一个字符实际上是第0个字符。
## Instructions
让我们尝试使用括号表示法将thirdLetterOfLastName设置为等于lastName变量的第三个字母。 暗示
如果卡住，请尝试查看secondLetterOfFirstName变量声明。
## Tests
```yml
tests:
- text: thirdLetterOfLastName变量的值应为v 。
testString: 'assert(thirdLetterOfLastName === "v", "The thirdLetterOfLastName variable should have the value of v.");'
- text: 您应该使用括号表示法。
testString: 'assert(code.match(/thirdLetterOfLastName\s*?=\s*?lastName\[.*?\]/), "You should use bracket notation.");'
```
## Challenge Seed
```js
// Example
var firstName = "Ada";
var secondLetterOfFirstName = firstName[1];
// Setup
var lastName = "Lovelace";
// Only change code below this line.
var thirdLetterOfLastName = lastName;
```
### After Test
```js
console.info('after the test');
```
## Solution
```js
// solution required
```