js 分割数组，将一个数组分成多个数组

function getNewArray(array, subGroupLength) {
  let index = 0;
  let newArray = [];
  while(index < array.length) {
      newArray.push(array.slice(index, index += subGroupLength));
  }
  return newArray;
}
 var arr= [1,2,3,4,5,6,7,8,9,10,11,12];;
 var nArr= getNewArray(arr, 8);
 //得到的nArr数组为：
  nArr[[1,2,3,4,5,6,7,8],[9,10,11,12]]