Split Array to Chunks

http://stackoverflow.com/questions/8495687/split-array-into-chunks

HTML

<span id="output"></span>

JavaScript

const splitToChunks = (arr, chunkSize, acc = []) => (
    arr.length > chunkSize ?
        splitToChunks(
            arr.slice(chunkSize),
            chunkSize,
            [...acc, arr.slice(0, chunkSize)]
        ) :
        [...acc, arr]
);

const chunks = splitToChunks([1, 2, 3, 4, 5, 6, 7], 3);
document.getElementById('output').innerText = chunks;