javascript - JS : how to get FIrst N elements of associative array

Question

我有那个 J 结构:

var rooms={};
rooms["room1"] = 10;
rooms["room2"] = 25;
rooms["room3"] = 15;
rooms["room4"] = 1;
rooms["room5"] = 10;
rooms["room6"] = 181;
rooms["somrthing"] = value;

我正在尝试编写一个函数来检索前 N 个元素

例如:

function getElements(limit) {
..
}

如果 limit = 3 将返回一个像这样的对象:

Object 
{room1: 10, room2: 25, room3: 15}

(前 3 个元素:我不需要订购!)

Answer 1

function getTopElements(limit) {
    var newRooms = {};
    var i = 0;
    for(r in rooms) {
        if(i < limit) {
            newRooms[r] = rooms[r];
            i++;
        }
        else
            return newRooms;
    }
    return newRooms;
}

jsfiddle DEMO