var arrange = function(arr){ var result = [], temp = []; arr.sort(function(source, dest){ return source - dest; }).concat(Infinity).reduce(function(source, dest){ temp.push(source); if(dest-source>1){ result.push(temp); temp = []; } return dest; }); return result; }; var arr=[3, 4, 13 ,14, 15, 17, 20, 22]; console.log(arrange(arr));