wehub-resource-sync
dde272c4b8
i18n - Build Validation / Validate i18n Builds (24) (push) Has been cancelled
CI - Node.js / Lint (24) (push) Has been cancelled
CI - Node.js / Build (24) (push) Has been cancelled
CI - Node.js / Test (24) (push) Has been cancelled
CI - Node.js / Test - Upcoming Changes (24) (push) Has been cancelled
CI - Node.js / Test - i18n (italian, 24) (push) Has been cancelled
CI - Node.js / Test - i18n (portuguese, 24) (push) Has been cancelled
CD - Docker - GHCR Images / Build and Push Images (push) Has been cancelled
92 lines
1.6 KiB
Markdown
92 lines
1.6 KiB
Markdown
---
|
|
id: 56533eb9ac21ba0edf2244e1
|
|
title: Nesting For Loops
|
|
challengeType: 1
|
|
forumTopicId: 18248
|
|
dashedName: nesting-for-loops
|
|
---
|
|
|
|
# --description--
|
|
|
|
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:
|
|
|
|
```js
|
|
const arr = [
|
|
[1, 2], [3, 4], [5, 6]
|
|
];
|
|
|
|
for (let i = 0; i < arr.length; i++) {
|
|
for (let 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.
|
|
|
|
# --instructions--
|
|
|
|
Modify function `multiplyAll` so that it returns the product of all the numbers in the sub-arrays of `arr`.
|
|
|
|
# --hints--
|
|
|
|
`multiplyAll([[1], [2], [3]])` should return `6`
|
|
|
|
```js
|
|
assert(multiplyAll([[1], [2], [3]]) === 6);
|
|
```
|
|
|
|
`multiplyAll([[1, 2], [3, 4], [5, 6, 7]])` should return `5040`
|
|
|
|
```js
|
|
assert(
|
|
multiplyAll([
|
|
[1, 2],
|
|
[3, 4],
|
|
[5, 6, 7]
|
|
]) === 5040
|
|
);
|
|
```
|
|
|
|
`multiplyAll([[5, 1], [0.2, 4, 0.5], [3, 9]])` should return `54`
|
|
|
|
```js
|
|
assert(
|
|
multiplyAll([
|
|
[5, 1],
|
|
[0.2, 4, 0.5],
|
|
[3, 9]
|
|
]) === 54
|
|
);
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
function multiplyAll(arr) {
|
|
let product = 1;
|
|
// Only change code below this line
|
|
|
|
// Only change code above this line
|
|
return product;
|
|
}
|
|
|
|
multiplyAll([[1, 2], [3, 4], [5, 6, 7]]);
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
function multiplyAll(arr) {
|
|
let product = 1;
|
|
for (let i = 0; i < arr.length; i++) {
|
|
for (let j = 0; j < arr[i].length; j++) {
|
|
product *= arr[i][j];
|
|
}
|
|
}
|
|
return product;
|
|
}
|
|
```
|