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Editor to share with you how to use Linq Lambda expressions to replace anonymous methods. I hope you will get something after reading this article. Let's discuss it together.

Linq Lambda expression

Linq Lambda expressions are a language feature that is similar to anonymous methods in many ways. In fact, if Linq Lambda expressions were first introduced into the language, there would be no need for anonymous methods. The basic concept here is that code can be treated as data. In C # 1.0, you can usually pass strings, integers, reference types, and so on to methods so that methods can manipulate those values. Anonymous methods and Linq Lambda expressions extend the range of values to include code blocks. This concept is common in functional programming.

Let's borrow the above example again and replace the anonymous method with an Linq Lambda expression:

IEnumerable locals = EnumerableExtensions.

Where (customers, c = > c.ZipCode = = 91822)

There are a few things to pay attention to. For beginners, Linq Lambda expressions are concise and to the point for many reasons. First, the delegate keyword is not used to introduce constructs. Instead, a new operator = > informs the compiler that this is not a regular expression. Second, the Customer type is inferred from use. In this example, the signature of the Where method is as follows:

Public static IEnumerable Where

(IEnumerable items, Func predicate)

The compiler can infer that "c" refers to the customer, because the * parameters of the Where method are IEnumerable, so T must in fact be Customer. With this knowledge, the compiler can also verify that Customer has a ZipCode member. *, there is no specified return keyword. In grammatical form, the returning member is omitted, but this is only for grammatical convenience. The result of the expression is still treated as a return value. Like anonymous methods, Linq Lambda expressions also support variable capture. For example, for a method that contains an Linq Lambda expression within the body of an Linq Lambda expression, you can reference its parameters or local variables:

Public IEnumerable

LocalCusts (IEnumerable customers, int zipCode)

{

Return EnumerableExtensions.

Where (customers, c = > c.ZipCode = = zipCode)

}

* Linq Lambda expressions support more verbose syntax, allowing you to explicitly specify types and execute multiple statements.

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