freeCodeCamp/curriculum/challenges/chinese/02-javascript-algorithms-and-data-structures/basic-javascript/nesting-for-loops.chinese.md

id, title, challengeType, videoUrl, localeTitle

id	title	challengeType	videoUrl	localeTitle
56533eb9ac21ba0edf2244e1	Nesting For Loops	1		嵌套循环

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：

var arr = [
[1,2]，[3,4]，[5,6]
]。
for（var i = 0; i <arr.length; i ++）{
for（var j = 0; j <arr [i] .length; j ++）{
的console.log（ARR [i] [j]）;
}
}

这个输出在每个子元件arr一次一个。注意，对于内部循环，我们检查arr[i]的.length ，因为arr[i]本身就是一个数组。

Instructions

修改函数multiplyAll ，使其乘以product变量乘以arr的子数组中的每个数字

Tests

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>");'

Challenge Seed

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]]);

Solution

// solution required