69 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			69 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 56533eb9ac21ba0edf2244b7 | |||
|  | title: Concatenating Strings with Plus Operator | |||
|  | challengeType: 1 | |||
|  | videoUrl: '' | |||
|  | localeTitle: 用Plus运算符连接字符串 | |||
|  | --- | |||
|  | 
 | |||
|  | ## Description
 | |||
|  | <section id="description">在JavaScript中,当<code>+</code>运算符与<code>String</code>值一起使用时,它被称为<dfn>连接</dfn>运算符。您可以通过<dfn>将</dfn>它们<dfn>连接</dfn>在一起来构建其他字符串中的新字符串。 <strong>例</strong> <blockquote> “我叫艾伦,'+'我连接起来。” </blockquote> <strong>注意</strong> <br>留意空间。连接不会在连接字符串之间添加空格,因此您需要自己添加它们。 </section> | |||
|  | 
 | |||
|  | ## Instructions
 | |||
|  | <section id="instructions">从字符串构建<code>myStr</code> <code>"This is the start. "</code>和<code>"This is the end."</code>使用<code>+</code>运算符。 </section> | |||
|  | 
 | |||
|  | ## Tests
 | |||
|  | <section id='tests'> | |||
|  | 
 | |||
|  | ```yml | |||
|  | tests: | |||
|  |   - text: <code>myStr</code>应该有一个值<code>This is the start. This is the end.</code> | |||
|  |     testString: 'assert(myStr === "This is the start. This is the end.", "<code>myStr</code> should have a value of <code>This is the start. This is the end.</code>");' | |||
|  |   - text: 使用<code>+</code>运算符构建<code>myStr</code> | |||
|  |     testString: 'assert(code.match(/([""]).*([""])\s*\+\s*([""]).*([""])/g).length > 1, "Use the <code>+</code> operator to build <code>myStr</code>");' | |||
|  |   - text: 应使用<code>var</code>关键字创建<code>myStr</code> 。 | |||
|  |     testString: 'assert(/var\s+myStr/.test(code), "<code>myStr</code> should be created using the <code>var</code> keyword.");' | |||
|  |   - text: 确保将结果分配给<code>myStr</code>变量。 | |||
|  |     testString: 'assert(/myStr\s*=/.test(code), "Make sure to assign the result to the <code>myStr</code> variable.");' | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Challenge Seed
 | |||
|  | <section id='challengeSeed'> | |||
|  | 
 | |||
|  | <div id='js-seed'> | |||
|  | 
 | |||
|  | ```js | |||
|  | // Example | |||
|  | var ourStr = "I come first. " + "I come second."; | |||
|  | 
 | |||
|  | // Only change code below this line | |||
|  | 
 | |||
|  | var myStr; | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </div> | |||
|  | 
 | |||
|  | 
 | |||
|  | ### After Test
 | |||
|  | <div id='js-teardown'> | |||
|  | 
 | |||
|  | ```js | |||
|  | console.info('after the test'); | |||
|  | ``` | |||
|  | 
 | |||
|  | </div> | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Solution
 | |||
|  | <section id='solution'> | |||
|  | 
 | |||
|  | ```js | |||
|  | // solution required | |||
|  | ``` | |||
|  | </section> |