let a=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21]; var submin =[]; for (var i = 0, len = a.length; i < len; i += 10) { submin.push(a.slice(i, Math.min(i + 10, len))) console.log('submin',submin); }