---
title: Chunky Monkey
---
# Chunky Monkey
---
## Problem Explanation
Our goal for this Algorithm is to split `arr` (first argument) into smaller chunks of arrays with the length provided by `size` (second argument). There are 4 green checks (objectives) our code needs to pass in order to complete this Algorithm:
1. `(['a', 'b', 'c', 'd'], 2)` is expected to be `[['a', 'b'], ['c', 'd']]`
2. `([0, 1, 2, 3, 4, 5], 3)` is expected to be `[[0, 1, 2], [3, 4, 5]]`
3. `([0, 1, 2, 3, 4, 5], 2)` is expected to be `[[0, 1], [2, 3], [4, 5]]`
4. `([0, 1, 2, 3, 4, 5], 4)` is expected to be `[[0, 1, 2, 3], [4, 5]]`
#### Relevant Links
* Array.push()
* Array.slice()
---
## Hints
### Hint 1
The links above suggest to use `Array.push()`, so let's start by first creating a new array to store the smaller arrays we will soon have like this:
```javascript
var newArray = [];
```
### Hint 2
Next we'll need a `for loop` to loop through `arr`.
### Hint 3
Finally, we need a method to do the actual splitting and we can use `Array.slice()` to do that. The key to this Algorithm is understanding how a `for loop`, `size`, `Array.slice()` and `Array.push()` all work together.
---
## Solutions
Solution 1 (Click to Show/Hide)
```javascript
function chunkArrayInGroups(arr, size) {
var temp = [];
var result = [];
for (var a = 0; a < arr.length; a++) {
if (a % size !== size - 1) temp.push(arr[a]);
else {
temp.push(arr[a]);
result.push(temp);
temp = [];
}
}
if (temp.length !== 0) result.push(temp);
return result;
}
```
#### Code Explanation
* Firstly, we create two empty arrays called `temp` and `result`, which we will eventually return.
* Our **for loop** loops until `a` is equal to or more than the length of the array in our test.
* Inside our loop, we push to `temp` using `temp.push(arr[a]);` if the remainder of `a / size` is not equal to `size - 1`.
* Otherwise, we push to `temp`, push `temp` to the `result` variable and reset `temp` to an empty array.
* Next, if `temp` isn't an empty array, we push it to `result`.
* Finally, we return the value of `result`.
#### Relevant Links
* Array.push()
* For Loops
Solution 2 (Click to Show/Hide)
```javascript
function chunkArrayInGroups(arr, size) {
// Break it up.
var arr2 = [];
for (var i = 0; i < arr.length; i += size) {
arr2.push(arr.slice(i, i + size));
}
return arr2;
}
```
#### Code Explanation
* First, we create an empty array `arr2` where we will store our 'chunks'.
* The for loop starts at zero, increments by `size` each time through the loop, and stops when it reaches `arr.length`.
* Note that this for loop does not loop through `arr`. Instead, we are using the loop to generate numbers we can use as indices to slice the array in the right locations.
* Inside our loop, we create each chunk using `arr.slice(i, i+size)`, and add this value to `arr2` with `arr2.push()`.
* Finally, we return the value of `arr2`.
#### Relevant Links
* Array.push()
* Array.slice()
* For Loops
Solution 3 (Click to Show/Hide)
```javascript
function chunkArrayInGroups(arr, size) {
// Break it up.
var newArr = [];
var i = 0;
while (i < arr.length) {
newArr.push(arr.slice(i, i + size));
i += size;
}
return newArr;
}
chunkArrayInGroups(["a", "b", "c", "d"], 2);
```
#### Code Explanation
* Firstly, we create two variables. `newArr` is an empty array which we will push to. We also have the `i` variable set to zero, for use in our while loop.
* Our while loop loops until `i` is equal to or more than the length of the array in our test.
* Inside our loop, we push to the `newArr` array using `arr.slice(i, i+size)`. For the first time it loops, it will look something like:
newArr.push(arr.slice(1, 1+2))
* After we push to `newArr`, we add the variable of `size` onto `i`.
* Finally, we return the value of `newArr`.
#### Relevant Links
* Array.push()
* Array.slice()
* While Loops
Solution 4 (Click to Show/Hide)
```javascript
function chunkArrayInGroups(arr, size) {
var newArr = [];
while (arr.length) {
newArr.push(arr.splice(0, size));
}
return newArr;
}
```
#### Code Explanation
* Firstly, we create a variable. `newArr` is an empty array which we will push to.
* Our `while` loop loops until the length of the array in our test is not 0.
* Inside our loop, we push to the `newArr` array using `arr.splice(0, size)`.
* For each iteration of `while` loop, it deletes `size` number of elements from the front of `arr` and push them as an array to `newArr`.
* Finally, we return the value of `newArr`.
#### Relevant Links
* Array.push()
* Array.splice()
* While Loops
Solution 5 (Click to Show/Hide)
```javascript
function chunkArrayInGroups(arr, size) {
if (arr.length <= size) {
return [arr];
} else {
return [arr.slice(0, size)].concat(
chunkArrayInGroups(arr.slice(size), size)
);
}
}
```
#### Code Explanation
* Array smaller than size is returned nested.
* For any array larger than size, it is split in two. First segment is nested and concatenated with second segment which makes a recursive call.
#### Relevant Links
* Recursion
* Array.slice()