当前位置:网站首页>C# Linq Demo
C# Linq Demo
2022-07-05 23:18:00 【ou. cs】
select
Assign values to new types
List<Students> studentsSource = new List<Students>()
{
new Students()
{
Id= 1,
Name="11",
ClassId=1,
Age=25,
},
new Students()
{
Id= 2,
Name="22",
ClassId=2,
Age=22,
},
new Students()
{
Id= 3,
Name="33",
ClassId=1,
Age=33,
},
new Students()
{
Id= 4,
Name="44",
ClassId=2,
Age=21,
},
new Students()
{
Id= 5,
Name="55",
ClassId=5,
Age=55,
},
};
var query =studentsSource.Select(x => new {
id=x.Id,age=x.Age>50?999:0});
foreach (var item in query)
{
Console.WriteLine(item.id);
Console.WriteLine(item.age);
Console.WriteLine("\n");
}
join
List<StuClass> stuClasses = new List<StuClass>()
{
new StuClass{
Id=1,ClassName="11"},
new StuClass{
Id=2,ClassName="22"},
new StuClass{
Id=3,ClassName="33"},
new StuClass{
Id=4,ClassName="44"},
};
// == Change it into equals
{
var query2 = from s in studentsSource
join c in stuClasses on s.ClassId equals c.Id
select new StuAndClass {
Id=s.Id,
ClassId=s.ClassId,
Age=s.Age,
ClassName=c.ClassName,
};
var query3 = studentsSource.Join(stuClasses, s => s.ClassId, c => c.Id, (s, c) => new StuAndClass
{
Id = s.Id,
ClassId = s.ClassId,
Age = s.Age,
ClassName = c.ClassName,
});
}
other
// Get the first data
//var query3 = studentsSource.Take(2);
//var query4 = studentsSource.Skip(2);
//var query5 = studentsSource.OrderBy(s=>s.Name);
var query2 = studentsSource.Select(s => s.Name);
var query6 = studentsSource.Where(s=>s.Name.Contains("1"));
边栏推荐
- [speech processing] speech signal denoising and denoising based on MATLAB low-pass filter [including Matlab source code 1709]
- How to quickly understand complex businesses and systematically think about problems?
- [untitled]
- Sum of two numbers, sum of three numbers (sort + double pointer)
- 2: Chapter 1: understanding JVM specification 1: introduction to JVM;
- LeetCode102. Sequence traversal of binary tree (output by layer and unified output)
- 14种神笔记方法,只需选择1招,让你的学习和工作效率提高100倍!
- 6-axis and 9-axis IMU attitude estimation
- [digital signal denoising] improved wavelet modulus maxima digital signal denoising based on MATLAB [including Matlab source code 1710]
- Common JVM tools and optimization strategies
猜你喜欢
Using LNMP to build WordPress sites
Selenium+pytest automated test framework practice
Development specification: interface unified return value format [resend]
Leetcode daily question 1189 The maximum number of "balloons" simple simulation questions~
Three.js-01 入门
Yiwen gets rid of the garbage collector
One article deals with the microstructure and instructions of class
Hainan Nuanshen tea recruits warmhearted people: recruitment of the product experience recommender of Nuanshen multi bubble honey orchid single cluster
Sum of two numbers, sum of three numbers (sort + double pointer)
Getting started stm32--gpio (running lantern) (nanny level)
随机推荐
SPSS analysis of employment problems of college graduates
TypeError: this. getOptions is not a function
Summary of binary tree recursive routines
UVA – 11637 Garbage Remembering Exam (组合+可能性)
Thoroughly understand JVM class loading subsystem
Krypton Factor purple book chapter 7 violent solution
Three.js-01 入门
Detailed explanation of pointer and array written test of C language
Starting from 1.5, build a micro Service Framework -- log tracking traceid
Go language implementation principle -- map implementation principle
芯源&立创EDA训练营——无刷电机驱动
14种神笔记方法,只需选择1招,让你的学习和工作效率提高100倍!
VS2010 writes DLL and unit test of dynamic link library, and transfers the correctness of DLL test
2022 G3 boiler water treatment simulation examination and G3 boiler water treatment simulation examination question bank
[screen recording] how to record in the OBS area
判断二叉树是否为完全二叉树
Go语言实现原理——Map实现原理
asp.net弹出层实例
【Note17】PECI(Platform Environment Control Interface)
Common JVM tools and optimization strategies