使用 LINQ 打印姓名以字符“S”开头的员工的 C# 程序

LINQ 被称为语言集成查询，它是在 .NET 3.5 中引入的。它使 .NET 语言能够生成查询以从数据源中检索数据。它消除了编程语言和数据库之间的不匹配，并且无论使用哪种类型的数据源，用于创建查询的语法都是相同的。在本文中，我们将学习如何使用 LINQ 打印姓名以字母“S”开头的员工的详细信息。因此，为了完成我们的任务，我们使用 Where() 方法。此方法根据谓词过滤给定的值序列或数组，要使用此方法，您需要在程序中添加 System.Linq 和 System.Collections.Generic 命名空间。

句法：

Where(IEnumerable, Func)

例子：

Input : List of Employees:
        {{id = 101, name = "Sravan", age = 12},
         {id = 102, name = "deepu",  age = 15},
         {id = 103, name = "manoja", age = 13},
         {id = 104, name = "Sathwik", age = 12},
         {id = 105, name = "Saran",  age = 15}}
Output : {{id = 105, name = "sravan", age = 15},
          {id = 104, name = "Sathwik",age = 12},
          {id = 105, name = "Saran",  age = 15}}
   
Input : List of Employees:
        {{id = 102, name = "deepu",  age = 15},
         {id = 103, name = "manoja", age = 13}}
Output : No Output

方法：

To find the list of employees whose name starts with letter ‘S’ follow the following steps:

1. Create a list of employees with three variables(Id, name, department, and salary).
2. Iterate through the employee details by using Where() function and get the employee details by choosing employee whose name starts with’ S’ using s => s.name[0] == ‘S’.
3. Now call the ToString() method.
4. Display the employee details.

例子：

C#

// C# program to display the details of those 
// employees whose name starts with character "S"
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
  
class Employee{
      
// Declare 4 variables - id, name, 
// department, and salary
int id; 
int salary;
string name;
string department;
  
// Get the to string method that returns 
// id, name, department, and salary
public override string ToString()
{
    return id + " " + name + " " + 
       salary + " " + department;
}
  
// Driver code
static void Main(string[] args)
{
      
    // Declare a list variable 
    List emp = new List()
    {
          
        // Create 5 Employee details
        new Employee{ id = 101, name = "Sravan", 
                      salary = 12000, department = "HR" },
        new Employee{ id = 102, name = "deepu", 
                      salary = 15000, department = "Development" },
        new Employee{ id = 103, name = "manoja", 
                      salary = 13000, department = "HR" },
        new Employee{ id = 104, name = "Sathwik", 
                      salary = 12000, department = "Designing" },
        new Employee{ id = 105, name = "Saran", 
                      salary = 15000, department = "Development" }
    };
      
    // Iterate the Employee by selecting Employee 
    // name starts with S
    IEnumerable result = emp.Where(x => x.name[0] == 'S');
      
    // Display employee details
    Console.WriteLine("ID  Name  Salary  Department");
    Console.WriteLine("++++++++++++++++++++++++++++");
    foreach (Employee e in result)
    {
          
        // Call the to string method
        Console.WriteLine(e.ToString());
    }    
}
}

输出：

ID  Name  Salary  Department
++++++++++++++++++++++++++++
101 Sravan 12000 HR
104 Sathwik 12000 Designing
105 Saran 15000 Development