63 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			63 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 56533eb9ac21ba0edf2244e1 | |||
|  | title: Nesting For Loops | |||
|  | challengeType: 1 | |||
|  | videoUrl: '' | |||
|  | localeTitle: 嵌套循环 | |||
|  | --- | |||
|  | 
 | |||
|  | ## Description
 | |||
|  | <section id="description">如果您有一个多维数组,则可以使用与先前路点相同的逻辑来遍历数组和任何子数组。这是一个例子: <blockquote> var arr = [ <br> [1,2],[3,4],[5,6] <br> ]。 <br> for(var i = 0; i <arr.length; i ++){ <br> for(var j = 0; j <arr [i] .length; j ++){ <br>的console.log(ARR [i] [j]); <br> } <br> } </blockquote>这个输出在每个子元件<code>arr</code>一次一个。注意,对于内部循环,我们检查<code>arr[i]</code>的<code>.length</code> ,因为<code>arr[i]</code>本身就是一个数组。 </section> | |||
|  | 
 | |||
|  | ## Instructions
 | |||
|  | <section id="instructions">修改函数<code>multiplyAll</code> ,使其乘以<code>product</code>变量乘以<code>arr</code>的子数组中的每个数字</section> | |||
|  | 
 | |||
|  | ## Tests
 | |||
|  | <section id='tests'> | |||
|  | 
 | |||
|  | ```yml | |||
|  | tests: | |||
|  |   - text: '<code>multiplyAll([[1],[2],[3]])</code>应该返回<code>6</code>' | |||
|  |     testString: 'assert(multiplyAll([[1],[2],[3]]) === 6, "<code>multiplyAll([[1],[2],[3]])</code> should return <code>6</code>");' | |||
|  |   - text: '<code>multiplyAll([[1,2],[3,4],[5,6,7]])</code>应返回<code>5040</code>' | |||
|  |     testString: 'assert(multiplyAll([[1,2],[3,4],[5,6,7]]) === 5040, "<code>multiplyAll([[1,2],[3,4],[5,6,7]])</code> should return <code>5040</code>");' | |||
|  |   - text: '<code>multiplyAll([[5,1],[0.2, 4, 0.5],[3, 9]])</code>应该返回<code>54</code>' | |||
|  |     testString: 'assert(multiplyAll([[5,1],[0.2, 4, 0.5],[3, 9]]) === 54, "<code>multiplyAll([[5,1],[0.2, 4, 0.5],[3, 9]])</code> should return <code>54</code>");' | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Challenge Seed
 | |||
|  | <section id='challengeSeed'> | |||
|  | 
 | |||
|  | <div id='js-seed'> | |||
|  | 
 | |||
|  | ```js | |||
|  | function multiplyAll(arr) { | |||
|  |   var product = 1; | |||
|  |   // Only change code below this line | |||
|  | 
 | |||
|  |   // Only change code above this line | |||
|  |   return product; | |||
|  | } | |||
|  | 
 | |||
|  | // Modify values below to test your code | |||
|  | multiplyAll([[1,2],[3,4],[5,6,7]]); | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </div> | |||
|  | 
 | |||
|  | 
 | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Solution
 | |||
|  | <section id='solution'> | |||
|  | 
 | |||
|  | ```js | |||
|  | // solution required | |||
|  | ``` | |||
|  | </section> |