Nesting For Loops : multiply value not included in sub arrays

JavaScript
1

Tell us what’s happening:
this is the code to multiply the numbers inside sub arrays , what if we have an array like this
[[1,2],4,[5,6,7]] and we want to include “4” in the multiplication operation , how can we do that ?

Your code so far

function multiplyAll(arr) {
  var product = 1;
  // Only change code below this line
  for(i = 0;i < arr.length;i++){
     for( j = 0;j < arr[i].length;j++){
        product *= arr[i][j] ;
      }
  }
  // Only change code above this line
  return product;
}

// Modify values below to test your code
multiplyAll([[1,2],4,[5,6,7]]);

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; rv:59.0) Gecko/20100101 Firefox/59.0.

Link to the challenge:
https://www.freecodecamp.org/challenges/nesting-for-loops

2

In your outer loop, you would want to check whether the item is an array or a number. If it’s an array you go into the nested loop and if it’s a number then you multiply it.

* If you don’t know how many arrays-deep a ragged array is, you might consider recursion.

1 Like