How to use LINQ to select into an object?

How to use LINQ to select into an object?

You can use LINQ to select data from a source and store it in a new object in C#. Here's an example of how to do this:

Let's say you have a List<Person> and you want to select only the names and ages of each person and store them in a new List<PersonInfo>:

using System;
using System.Collections.Generic;
using System.Linq;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class PersonInfo
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class Program
{
    static void Main(string[] args)
    {
        List<Person> people = new List<Person>()
        {
            new Person() { Name = "John", Age = 25 },
            new Person() { Name = "Mary", Age = 30 },
            new Person() { Name = "Bob", Age = 40 },
        };

        List<PersonInfo> peopleInfo = people.Select(p => new PersonInfo()
        {
            Name = p.Name,
            Age = p.Age
        }).ToList();

        foreach (PersonInfo info in peopleInfo)
        {
            Console.WriteLine("Name: {0}, Age: {1}", info.Name, info.Age);
        }
    }
}

In this example, we have a List<Person> with three people. We use LINQ's Select method to select only the Name and Age properties of each person and store them in a new List<PersonInfo> using the new operator. Finally, we iterate over the new List<PersonInfo> and output the Name and Age properties of each person.

Note that the Select method returns an IEnumerable<T> which needs to be converted to a List<PersonInfo> using the ToList method at the end. Also, the new operator is used to create a new PersonInfo object for each person in the Select method.

Examples

  1. "LINQ select into object example"

    Code Implementation:

    var resultObject = itemList.Select(item => new ResultObject
{
    Property1 = item.Property1,
    Property2 = item.Property2,
    // Additional properties
});

    Description: This query demonstrates how to use LINQ to select specific properties from items in a collection into a new ResultObject.

  2. "C# LINQ select into anonymous type"

    Code Implementation:

    var result = itemList.Select(item => new
{
    Name = item.Name,
    Price = item.Price
    // Additional properties
});

    Description: Illustrates the use of LINQ to select specific properties into an anonymous type.

  3. "LINQ select into custom object with constructor"

    Code Implementation:

    var customObjects = itemList.Select(item => new CustomObject(item.Property1, item.Property2));

    Description: This query showcases selecting properties into a custom object using a constructor.

  4. "C# LINQ select into dictionary"

    Code Implementation:

    var dictionary = itemList.ToDictionary(item => item.KeyProperty, item => item.ValueProperty);

    Description: Demonstrates using LINQ to convert a collection into a dictionary, selecting key-value pairs.

  5. "LINQ select into DTO (Data Transfer Object)"

    Code Implementation:

    var dtoList = itemList.Select(item => new ItemDTO
{
    Name = item.Name,
    Quantity = item.Quantity
    // Additional properties
});

    Description: Shows how to use LINQ to project properties into a Data Transfer Object (DTO).

  6. "C# LINQ select into list of strings"

    Code Implementation:

    var stringList = itemList.Select(item => item.Name).ToList();

    Description: This query selects a specific property into a list of strings using LINQ.

  7. "LINQ select into tuple"

    Code Implementation:

    var tupleList = itemList.Select(item => (item.Name, item.Price)).ToList();

    Description: Illustrates selecting multiple properties into a tuple using LINQ.

  8. "C# LINQ select into dynamic object"

    Code Implementation:

    var dynamicObjectList = itemList.Select(item => new { item.Name, item.Price }).ToList();

    Description: Shows how to use LINQ to select properties into a dynamic object.

  9. "LINQ select into nested object"

    Code Implementation:

    var nestedObjectList = itemList.Select(item => new ParentObject
{
    ChildObject = new ChildObject
    {
        Property1 = item.Property1,
        Property2 = item.Property2
    },
    // Additional properties
});

    Description: This query demonstrates selecting properties into a nested object structure.

  10. "C# LINQ select into object with condition"

    Code Implementation:

    var filteredObjects = itemList.Where(item => item.Quantity > 10)
                             .Select(item => new FilteredObject
                             {
                                 Name = item.Name,
                                 Quantity = item.Quantity
                                 // Additional properties
                             });

    Description: Illustrates using LINQ to filter items based on a condition and then selecting properties into a new object.

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