javascript - 计算数组中不同元素的数量

Question

我有来自服务器到数据表的数据。我已成功填充表格，但在页脚回调中我想进行一些统计。

假设我有这样的数据:

var data = [{
    date: '2013-05-12',
    holiday: "One type of holiday",
    dayType: "Weekend"
}, {
    date: '2013-05-13',
    holiday: "Another type",
    dayType: "Weekend"
}, {
    date: '2013-05-14',
    holiday: "Another type",
    dayType: "Work"
}, {
    date: '2013-05-15',
    holiday: "",
    dayType: "Work"
}];

我想计算不同假期的天数。

这是我想要得到的结果:

var summary= [
{
    "One type of holiday": {
        "work": 0,
        "weekend": 1
    }
},
{
    "Another type": {
        "work": 1,
        "weekend": 1
    }
}];

I've created a very simple code to simply aggregate holidays :

for (var i = 0; i < data.length; i++) {
    //console.log(data[i].holiday);
    /*other stuff here*/
    if (data[i].holiday.length > 0) 
        summary[data[i].holiday] = summary[data[i].holiday] + 1 || 1;
}

但这给了我无效的结果，因为在我的数据数组中假期包含空格。

我需要一种方法来解决这个问题并根据 dayType 分割假期。

<小时/>

我的解决方案: My version of answer :

var summary = {}, d, tmp, type;
for (var i = 0; i < data.length; i++) {
    var d = data[i];
    if (d.holiday.length > 0) {
        type = d.dayType == 'Weekend' || d.dayType == 'Free' ? 'Weekend' : 'Work';
        tmp = summary[d.holiday];
        if (!tmp) {
            tmp = {
                Weekend: 0,
                Work: 0
            };
            summary[d.holiday] = tmp;
        }
        summary[d.holiday][type] += 1;
    }
}

因为这是 @Arun 答案的修改版本，所以我不会将其作为独立答案发布。
我发现我的版本更容易理解，希望有人觉得它有用。

Answer 1

尝试

var summary = [], summaryMap = {}, d, map, m;
for (var i = 0; i < data.length; i++) {
    var d = data[i];
    map = summaryMap[d.holiday];
    if(!map){
        map = {
            Work: 0,
            Weekend: 0
        };
        m = {};
        m[d.holiday] = map;
        summary.push(m);
        summaryMap[d.holiday] = map;
    }
    map[d.dayType] += 1;
}
console.log(summary);
console.log(JSON.stringify(summary));

演示:Fiddle