C# 如何在c中从JSON字符串中检索不同对象类型的计数#

我有一个包含数据的单数组json字符串：

[{"Name":"John","Age":"22"}, {"Name":"Jack","Age":"56"}, {"Name":"John","Age":"82"}, {"Name":"Jack","Age":"95"}]

我已经反序列化了数据，并成功地将数据写入jquery数据表。但是，我现在想在datatable中添加一列，以包含john和jack姓名的计数，这些姓名都在一列中。我可以通过在循环中说以下内容来获得单个计数：

if (people[i].Name == "John")
   {
                name_count++;
   }
if (people[i].Name == "Jack")
   {
          name_count2++;
   }

---

如何使这些数据显示在与包含jack或john名称的行匹配的一列中？我用的是C#。提前感谢

我建议使用下划线.js(http://documentcloud.github.com/underscore). 您可以轻松实现所需的任何类型的map/reduce/select。这里有一个例子：

var people = [{"Name":"John","Age":"22"}, {"Name":"Jack","Age":"56"}, {"Name":"John","Age":"82"}, {"Name":"Jack","Age":"95"}];

var num_johns = _(people).select(function(obj){ 
    return obj.Name === 'John'}).length;

alert(num_johns); //alerts 2

---

您甚至可以更进一步，用一些curry来计算select函数，这取决于您的具体问题。

我建议使用下划线.js(http://documentcloud.github.com/underscore). 您可以轻松实现所需的任何类型的map/reduce/select。这里有一个例子：

var people = [{"Name":"John","Age":"22"}, {"Name":"Jack","Age":"56"}, {"Name":"John","Age":"82"}, {"Name":"Jack","Age":"95"}];

var num_johns = _(people).select(function(obj){ 
    return obj.Name === 'John'}).length;

alert(num_johns); //alerts 2

---

您甚至可以更进一步，用一些currying来计算select函数，这取决于您的具体问题。

您可以对数组进行linq分组

    var peeps = from person in people 
        group person by person.name into bucket 
        select new { name = bucket.Key, count = bucket.Count() };

这将创建一个具有名称和计数属性的可枚举匿名类型，您可以对其进行迭代以获取名称的名称和计数，例如：

class Guy
    {
        public int age; public string name;
        public Guy( int age, string name ) {
            this.age = age;
            this.name = name;
        }

    }

    class Program
    {
        static void Main( string[] args ) {
            var GuyArray = new Guy[] { 
            new Guy(22,"John"),new Guy(25,"John"),new Guy(27,"John"),new Guy(29,"John"),new Guy(12,"Jack"),new Guy(32,"Jack"),new Guy(52,"Jack"),new Guy(100,"Abe")};

        var peeps = from f in GuyArray group f by f.name into g select new { name = g.Key, count = g.Count() };

            foreach ( var record in peeps ) {
                Console.WriteLine( record.name + " : " + record.count );
            }

        }
    }

将发出：

John : 4
Jack : 3
Abe : 1

---

您可以对数组进行linq分组

    var peeps = from person in people 
        group person by person.name into bucket 
        select new { name = bucket.Key, count = bucket.Count() };

这将创建一个具有名称和计数属性的可枚举匿名类型，您可以对其进行迭代以获取名称的名称和计数，例如：

class Guy
    {
        public int age; public string name;
        public Guy( int age, string name ) {
            this.age = age;
            this.name = name;
        }

    }

    class Program
    {
        static void Main( string[] args ) {
            var GuyArray = new Guy[] { 
            new Guy(22,"John"),new Guy(25,"John"),new Guy(27,"John"),new Guy(29,"John"),new Guy(12,"Jack"),new Guy(32,"Jack"),new Guy(52,"Jack"),new Guy(100,"Abe")};

        var peeps = from f in GuyArray group f by f.name into g select new { name = g.Key, count = g.Count() };

            foreach ( var record in peeps ) {
                Console.WriteLine( record.name + " : " + record.count );
            }

        }
    }

将发出：

John : 4
Jack : 3
Abe : 1

---

谢谢你的回复。然而，我正在寻找一个c#解决方案。实际上，我有一个程序的副本，它使用客户端代码实现了完整的功能和正确的结果。但是，由于处理量太大，它现在变得非常慢，需要一个C#的替代解决方案。感谢您的回复。然而，我正在寻找一个c#解决方案。实际上，我有一个程序的副本，它使用客户端代码实现了完整的功能和正确的结果。然而，由于处理量很大，它现在变得非常慢，需要一个C#中的替代解决方案。