gistfile1.txt

function splitArrayInArraysBySection (arr) {
    const returnsObject = arr.reduce((newArrSofar, item) => {
		const toAdd = newArrSofar[item.section] ? [...newArrSofar[item.section], item] : [item]
			return {
				...newArrSofar,
				[item.section]: toAdd
			}	
	},{});
  return Object.values(returnsObject); // to return array actually
}


const check = [
	{id: 'a', section: 0},
	{id: 'b', section: 1},
	{id: 'c', section: 2},
	{id: 'd', section: 1}
]

splitArrayInArraysBySection(check)