C# LINQ Introduction
Projections with Select
With LINQ, you also can transform data from one representation into another.
The Select(transformationFunction)
method allows you to project each element of a sequence into a new form.
The method takes a transformation function as argument.
Here is a simple example. From a collection of numbers, calculate the square number of each element.
var numbers = new [] { 1, 2, 3, 4, 5 };
var squares = numbers.Select(x => x * x); // 1, 4, 9, 16, 25
In the example above, the transformation function x => x * x
is called for evrey element of numbers
.
This projects the sequence of integers (numbers
) to a new sequence of integers (squares
).
But with Select
you can also transform the type of a sequence.
Here is another example. From a collection of person objects, select only the names.
The example above projects the IEnumerable<Person>
to an IEnumerable<string>
.