66 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			66 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 56533eb9ac21ba0edf2244b8 | ||
|  | title: Concatenating Strings with the Plus Equals Operator | ||
|  | challengeType: 1 | ||
|  | videoUrl: '' | ||
|  | localeTitle: 使用Plus Equals运算符连接字符串 | ||
|  | --- | ||
|  | 
 | ||
|  | ## Description
 | ||
|  | <section id="description">我们还可以使用<code>+=</code>运算符将字符串<dfn>连接</dfn>到现有字符串变量的末尾。这对于在多行上打破长字符串非常有帮助。 <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">通过连接这两个字符串来构建<code>myStr</code>几行: <code>"This is the first sentence. "</code>和<code>"This is the second sentence."</code>使用<code>+=</code>运算符。使用<code>+=</code>运算符,类似于它在编辑器中的显示方式。首先将第一个字符串分配给<code>myStr</code> ,然后添加第二个字符串。 </section> | ||
|  | 
 | ||
|  | ## Tests
 | ||
|  | <section id='tests'> | ||
|  | 
 | ||
|  | ```yml | ||
|  | tests: | ||
|  |   - text: <code>myStr</code>应该有一个值<code>This is the first sentence. This is the second sentence.</code> | ||
|  |     testString: 'assert(myStr === "This is the first sentence. This is the second sentence.", "<code>myStr</code> should have a value of <code>This is the first sentence. This is the second sentence.</code>");' | ||
|  |   - text: 使用<code>+=</code>运算符构建<code>myStr</code> | ||
|  |     testString: 'assert(code.match(/\w\s*\+=\s*[""]/g).length > 1 && code.match(/\w\s*\=\s*[""]/g).length > 1, "Use the <code>+=</code> operator to build <code>myStr</code>");' | ||
|  | 
 | ||
|  | ``` | ||
|  | 
 | ||
|  | </section> | ||
|  | 
 | ||
|  | ## Challenge Seed
 | ||
|  | <section id='challengeSeed'> | ||
|  | 
 | ||
|  | <div id='js-seed'> | ||
|  | 
 | ||
|  | ```js | ||
|  | // Example | ||
|  | var ourStr = "I come first. "; | ||
|  | ourStr += "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> |