2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								---
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								id: 587d7db4367417b2b2512b92
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								title: 提取匹配项
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								challengeType: 1
							 | 
						
					
						
							
								
									
										
										
										
											2020-08-04 15:14:01 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								forumTopicId: 301340
							 | 
						
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								dashedName: extract-matches
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								---
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								# --description--
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								到目前为止,只是检查了一个匹配模式是否存在于字符串中。 还可以使用 `.match()` 方法来提取找到的实际匹配项。
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								可以使用字符串来调用 `.match()` 方法,并在括号内传入正则表达式。
							 | 
						
					
						
							
								
									
										
										
										
											2021-02-06 04:42:36 +00:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								请看下面的举例:
							 | 
						
					
						
							
								
									
										
										
										
											2020-08-04 15:14:01 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								"Hello, World!".match(/Hello/);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let ourStr = "Regular expressions";
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let ourRegex = /expressions/;
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								ourStr.match(ourRegex);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								这里第一个 `match` 将返回 `["Hello"]` 第二个将返回 `["expressions"]`。
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								请注意, `.match` 语法是目前为止一直使用的 `.test` 方法中的“反向”:
							 | 
						
					
						
							
								
									
										
										
										
											2021-02-06 04:42:36 +00:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								'string'.match(/regex/);
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								/regex/.test('string');
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								# --instructions--
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								利用 `.match()` 方法提取单词 `coding`。
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								# --hints--
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								`result` 应该有字符串 `coding`
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								assert(result.join() === 'coding');
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								您的 regex `codingRegex` 应该搜索字符串 `coding`
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								assert(codingRegex.source === 'coding');
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-03-14 21:20:39 -06:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								您应该使用 `.match()` 方法。
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								assert(code.match(/\.match\(.*\)/));
							 | 
						
					
						
							
								
									
										
										
										
											2018-10-10 18:03:03 -04:00
										 
									 
								 
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							
								
									
										
										
										
											2020-08-04 15:14:01 +08:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								# --seed--
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								## --seed-contents--
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let extractStr = "Extract the word 'coding' from this string.";
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let codingRegex = /change/; // Change this line
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let result = extractStr; // Change this line
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2020-12-16 00:37:30 -07:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								# --solutions--
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								
							 | 
						
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00
										 
									 
								 
							 | 
							
								
									
										
									
								
							 | 
							
								
							 | 
							
							
								```js
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let extractStr = "Extract the word 'coding' from this string.";
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let codingRegex = /coding/; // Change this line
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								let result = extractStr.match(codingRegex); // Change this line
							 | 
						
					
						
							| 
								
							 | 
							
								
							 | 
							
								
							 | 
							
							
								```
							 |