---
id: 587d7db7367417b2b2512b9d
title: Match Beginning String Patterns
challengeType: 1
videoUrl: ''
localeTitle: 匹配开始字符串模式
---
## Description
先前的挑战表明，正则表达式可用于寻找许多匹配。它们还用于搜索字符串中特定位置的模式。在之前的挑战中，您使用character set内的caret符（ ^ ）来创建[^thingsThatWillNotBeMatched]形式的negated character set 。在character set ， caret用于在字符串的开头搜索模式。 让firstString =“Ricky是第一个，可以找到。”;
让firstRegex = / ^ Ricky /;
firstRegex.test（firstString）;
//返回true
让notFirst =“你现在找不到Ricky了。”;
firstRegex.test（notFirst）;
//返回false
## Instructions
使用正则表达式中的caret只能在字符串rickyAndCal的开头找到"Cal" 。
## Tests
```yml
tests:
- text: 你的正则表达式应该用大写字母搜索"Cal" 。
testString: 'assert(calRegex.source == "^Cal", "Your regex should search for "Cal" with a capital letter.");'
- text: 你的正则表达式不应该使用任何标志。
testString: 'assert(calRegex.flags == "", "Your regex should not use any flags.");'
- text: 你的正则表达式应该匹配字符串开头的"Cal" 。
testString: 'assert(calRegex.test("Cal and Ricky both like racing."), "Your regex should match "Cal" at the beginning of the string.");'
- text: 您的正则表达式不应与字符串中间的"Cal"匹配。
testString: 'assert(!calRegex.test("Ricky and Cal both like racing."), "Your regex should not match "Cal" in the middle of a string.");'
```
## Challenge Seed
```js
let rickyAndCal = "Cal and Ricky both like racing.";
let calRegex = /change/; // Change this line
let result = calRegex.test(rickyAndCal);
```
## Solution
```js
// solution required
```