Rashid - 1 year ago 94

Javascript Question

I am expected to write a function that splits an array (first argument) into groups the length of size (second argument) and returns them as a two-dimensional array.

Therefore, chunkArrayInGroups(["a", "b", "c", "d"], 2) should return [["a", "b"], ["c", "d"]]

`function chunkArrayInGroups(arr, size) {`

// Break it up.

var result=[];

for (var i=0;i<=Math.ceil(arr.length/size);i++){

var j=0;

if(i!== 0){

j+=size;

size+=size;

}

result[i] = arr.slice(j , size);

}

//return arr.length/size

//results in 1.5

return result;

// results [["a", "b"], ["c", "d"]]

}

chunkArrayInGroups(["a", "b", "c", "d"], 2);

I am getting the desired result but I'm not very satisfied with my solution,

also, more importantly

"if" arr.length = 4; and, size =2; then why is arr.length/size = 1 ?

shouldn't it be 4/2=2?

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Answer Source

You modify size inside the loop. This basically doubles the size at every step. The fact that your example only has two sub-arrays hides this problem. Try larger arrays to see the problem in the result.

To fix this, declare j outside of the loop. Add the size to j after slicing.

**Edit**: Code, as requested

```
function chunkArrayInGroups(arr, size) {
var result = [];
var j = 0;
for (var i = 0; i <= Math.ceil(arr.length / size); i++) {
result[i] = arr.slice(j, j + size);
j = j + size;
}
return result;
}
```

Or, slightly simplified:

```
function chunkArrayInGroups(arr, size) {
var result = [];
var pos = 0;
while (pos < size) {
result.push(arr.slice(pos, pos + size);
pos += size;
}
return result;
}
```