linq.js的用法
linq.js 详细介绍
linq.js 是一个 JavaScript 实现的 LINQ。
主要特性：
实现所有 .NET 4.0 的方法
complete lazy evaluation
full IntelliSense support for VisualStudio
two versions - linq.js and jquery.linq.js (jQuery plugin)
support Windows Script Host
binding for Reactive Extensions for JavaScript(RxJS) and IntelliSense Generator -> see documentation
NuGet install support
示例代码：
var jsonArray = [
{ "user": { "id": 100, "screen_name": "d_linq" }, "text": "to objects" },
{ "user": { "id": 130, "screen_name": "c_bill" }, "text": "g" },
{ "user": { "id": 155, "screen_name": "b_mskk" }, "text": "kabushiki kaisha" },
{ "user": { "id": 301, "screen_name": "a_xbox" }, "text": "halo reach" }
]
// ["b_mskk:kabushiki kaisha", "c_bill:g", "d_linq:to objects"]
var queryResult = Enumerable.From(jsonArray)
.Where(function (x) { return x.user.id < 200 })
.OrderBy(function (x) { return x.user.screen_name })
.Select(function (x) { return x.user.screen_name + ':' + x.text })
.ToArray();
// shortcut! string lambda selector
var queryResult2 = Enumerable.From(jsonArray)
.Where("$.user.id < 200")
.OrderBy("$.user.screen_name")
.Select("$.user.screen_name + ':' + $.text")
.ToArray();
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
用途：方便js操作查询json数据。
下载网址：http://jslinq.codeplex.com/
使用方法：只需要引用linq.js即可。
查询方法：
一、where查询
var myList = [
{ Name: "Jim", Age: 20 },
{ Name: "Kate", Age: 21 },
{ Name: "Lilei", Age: 18 },
{ Name: "John", Age: 14 },
{ Name: "LinTao", Age: 25 }
];
var arrRes = Enumerable.From(myList).Where("x=>x.Name=='Jim'").ToArray();
二、排序：OrderBy
var myList = [
{ Name: "Jim", Age: 20 },
{ Name: "Kate", Age: 21 },
{ Name: "Lilei", Age: 18 },
{ Name: "John", Age: 14 },
{ Name: "LinTao", Age: 25 }
];
var arrRes = Enumerable.From(myList).OrderBy("x=>x.Age").ToArray();//降序OrderByDescending()
三、去重：Distinct
var myList = [
{ Name: "Jim", Age: 20 },
{ Name: "Kate", Age: 20 },
{ Name: "Lilei", Age: 20 },
{ Name: "John", Age: 14 },
{ Name: "LinTao", Age: 25 }
];
var arrRes = Enumerable.From(myList).Distinct("x=>x.Age").ToArray();
四、遍历：ForEach
var myList = [
{ Name: "Jim", Age: 20 },
{ Name: "Kate", Age: 20 },
{ Name: "Lilei", Age: 20 },
{ Name: "John", Age: 14 },
{ Name: "LinTao", Age: 25 }
];
Enumerable.From(myList).ForEach(function(value, index){
document.write("值="+value+",索引="+index);
});
五、取唯一对象：First、FirstOrDefault、Last、LastOrDefault、Single、SingleOrDefault
var myList = [
{ Name: "Jim", Age: 20 },
{ Name: "Kate", Age: 20 },
{ Name: "Lilei", Age: 20 },
{ Name: "John", Age: 14 },
{ Name: "LinTao", Age: 25 }
];
var arrRes = Enumerable.From(myList).FirstOrDefault("x=>x.Age>18");
六、Skip、Take
Enumerable.Range(1,10).Skip(5)//结果[6,7,8,9,10]
Enumerable.Range(1,10).Take(5)//结果[1,2,3,4,5]
