---
id: bd7123c9c448eddfaeb5bdef
title: Find the Length of a String
challengeType: 1
videoUrl: ''
localeTitle: 找到字符串的长度
---
## Description
您可以通过在字符串变量或字符串文字后面写.length来查找String值的长度。 "Alan Peter".length; // 10例如，如果我们创建了一个变量var firstName = "Charles" ，我们可以通过使用firstName.length属性找出字符串"Charles"长度。
## Instructions
使用.length属性计算lastName变量中的字符数，并将其分配给lastNameLength 。
## Tests
```yml
tests:
- text: lastNameLength应该等于8。
testString: 'assert((function(){if(typeof lastNameLength !== "undefined" && typeof lastNameLength === "number" && lastNameLength === 8){return true;}else{return false;}})(), "lastNameLength should be equal to eight.");'
- text: 您应该使用.length来获取lastName的长度，如下所示： lastName.length 。
testString: 'assert((function(){if(code.match(/\.length/gi) && code.match(/\.length/gi).length >= 2 && code.match(/var lastNameLength \= 0;/gi) && code.match(/var lastNameLength \= 0;/gi).length >= 1){return true;}else{return false;}})(), "You should be getting the length of lastName by using .length like this: lastName.length.");'
```
## Challenge Seed
```js
// Example
var firstNameLength = 0;
var firstName = "Ada";
firstNameLength = firstName.length;
// Setup
var lastNameLength = 0;
var lastName = "Lovelace";
// Only change code below this line.
lastNameLength = lastName;
```
### After Test
```js
console.info('after the test');
```
## Solution
```js
// solution required
```