LINQ preview: Where, Select, OrderBy, Take/Skip; deferred execution
Build small LINQ pipelines over IEnumerable : filter with Where, transform with Select, order with OrderBy, and learn deferred execution vs materialization.
LINQ overview
Goal: Use tiny LINQ pipelines to filter, transform, and order data.
- Where (filter)
- Select (map)
- OrderBy, Take/Skip
- Deferred execution & materialization
Where + Select
Chain Where (filter) then Select (transform). Read left-to-right.
using System;
using System.Linq;
public class Program
{
public static void Main(string[] args)
{
int[] data = new int[] { 1, 2, 3, 4, 5, 6 };
// Filter even numbers, then square them
var query = data.Where(x => x % 2 == 0)
.Select(x => x * x);
foreach (int n in query)
{
Console.WriteLine(n); // 4, 16, 36
}
}
}
All lessons in this course
- Arrays, slicing, List , Dictionary
- foreach patterns; collection initializers
- LINQ preview: Where, Select, OrderBy, Take/Skip; deferred execution