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Nesting For Loops |
Nesting For Loops
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🏁 Problem Explanation:
If you have a multi-dimensional array, you can use the same logic as the prior waypoint to loop through both the array and any sub-arrays.
Here is an example:
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++) {
console.log(arr[i][j]);
}
}
This outputs each sub-element in arr
one at a time. Note that for the inner loop, we are checking the length of arr[i], since arr[i] is itself an array.
- Modify function
multiplyAll
so that it multiplies theproduct
variable by each number in the sub-arrays ofarr
. - Make sure the second for loop is nested inside the first.
Relevant Links
- Nest One Array Within Another Array
- Iterate Through An Array With A For Loop
- Accessing Nested Arrays
💬 Hint: 1
Make sure to check with length
and not the overall array.
try to solve the problem now
💬 Hint 2
Use both i
and j
when multiplying the product.
try to solve the problem now
💬 Hint 3
Remember to use arr[i]
when you multiply the sub-arrays with the product
variable.
try to solve the problem now
Spoiler Alert!
Solution Ahead!
🔰 Basic Code Solution:
function multiplyAll(arr) {
var product = 1;
// Only change code below this line
for(var i=0; i < arr.length; i++){
for (var j=0; j < arr[i].length; j++){
product = product * arr[i][j];
}
}
// Only change code above this line
return product;
}
// Modify values below to test your code
multiplyAll([[1,2],[3,4],[5,6,7]]);
🚀 Run Code
Code Explanation:
- We check the length of
arr
in thei
for loop and thearr[i]
length in thej
for loop. - We multiply the
product
variable by itself because it equals 1, and then multiply it by the sub-arrays. - The two sub-arrays to multiply are
arr[i]
andj
.
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