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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 587d7db7367417b2b2512b9d
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: Match Beginning String Patterns
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								challengeType: 1
							 
						 
					
						
							
								
									
										
										
										
											2019-08-05 09:17:33 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								forumTopicId: 301349
							 
						 
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								dashedName: match-beginning-string-patterns
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --description--
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								Prior challenges showed that regular expressions can be used to look for a number of matches. They are also used to search for patterns in specific positions in strings.
							 
						 
					
						
							
								
									
										
										
										
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								In an earlier challenge, you used the caret character (`^` ) inside a character set to create a negated character set in the form `[^thingsThatWillNotBeMatched]` . Outside of a character set, the caret is used to search for patterns at the beginning of strings.
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let firstString = "Ricky is first and can be found.";
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let firstRegex = /^Ricky/;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								firstRegex.test(firstString);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let notFirst = "You can't find Ricky now.";
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								firstRegex.test(notFirst);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								The first `test`  call would return `true` , while the second would return `false` .
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --instructions--
  
						 
					
						
							
								
									
										
										
										
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								Use the caret character in a regex to find `Cal`  only in the beginning of the string `rickyAndCal` .
							 
						 
					
						
							
								
									
										
										
										
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								# --hints--
  
						 
					
						
							
								
									
										
										
										
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								Your regex should search for the string `Cal`  with a capital letter.
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(calRegex.source == '^Cal');
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								Your regex should not use any flags.
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(calRegex.flags == '');
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
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								Your regex should match the string `Cal`  at the beginning of the string.
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
									
										
										
										
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								assert(calRegex.test('Cal and Ricky both like racing.'));
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								Your regex should not match the string `Cal`  in the middle of a string.
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(!calRegex.test('Ricky and Cal both like racing.'));
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# --seed--
  
						 
					
						
							
								
									
										
										
										
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								## --seed-contents--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let rickyAndCal = "Cal and Ricky both like racing.";
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let calRegex = /change/; // Change this line
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let result = calRegex.test(rickyAndCal);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
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								# --solutions--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								let rickyAndCal = "Cal and Ricky both like racing.";
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let calRegex = /^Cal/; // Change this line
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								let result = calRegex.test(rickyAndCal);
							 
						 
					
						
							
								
									
										
										
										
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								```