Split array into chunks of N length [duplicate]

Question

How to split an array (which has 10 items) into 4 chunks, which contain a maximum of n items.

var a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']; //a function splits it to four arrays. console.log(b, c, d, e); 

And it prints:

['a', 'b', 'c'] ['d', 'e', 'f'] ['j', 'h', 'i'] ['j'] 

The above assumes n = 3, however, the value should be dynamic.

Thanks

Answer 1

It could be something like that:

var a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];  var arrays = [], size = 3;      while (a.length > 0)   arrays.push(a.splice(0, size));  console.log(arrays);

See splice Array's method.

An alternative method that does not mutate the array, beside create a shallow copy of it before chunk it, could be done by using slice and a for…loop:

var a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];  var arrays = [], size = 3;      for (let i = 0; i < a.length; i += size)    arrays.push(a.slice(i, i + size));  console.log(arrays);

While a more functional programming oriented approach, could be:

const chunks = (a, size) =>     Array.from(         new Array(Math.ceil(a.length / size)),         (_, i) => a.slice(i * size, i * size + size)     );  let a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];  console.log(chunks(a, 3)); console.log(chunks(a, 2));

See Array.from and how new Array(n) works, specifically.