js如何判断一组数字是否连续,得到一个临时数组[[3,4],[13,14,15],[17],[20],[22]];

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));