Lambda Expressions vs Delegate Types: Are They Truly Different at Compile Time?

Lambda Expressions and Delegate Types: Delving into the Differences

In C#, lambda expressions and delegate keywords offer similar functionality for representing anonymous methods. However, a key question arises: is there a discernible difference between these two notations when compiled?

Short Answer: No Notable Difference

Whether a lambda expression is written using the syntax delegate { x = 0; } or the shorthand () => { x = 0 }, the compiler compiles both to an equivalent anonymous delegate.

Extended Explanation

While the short answer is clear, a slight variation exists in certain scenarios. If the lambda expression is assigned to a delegate type (e.g., Func or Action), an anonymous delegate is created. However, if the lambda expression is assigned to an expression type, an expression tree is generated, rather than an anonymous delegate. This expression tree can be further compiled into an anonymous delegate when needed.

Distinction in LINQ Implementations

In the context of Language Integrated Query (LINQ), the usage of delegate types (System.Func) and expression types (System.Linq.Queryable) differs. LINQ in-memory operations utilize System.Linq.Enumerable, which operates with anonymous methods. Conversely, LINQ to SQL and similar implementations employ expression trees, which are then translated into platform-specific SQL.

The above is the detailed content of Lambda Expressions vs Delegate Types: Are They Truly Different at Compile Time?. For more information, please follow other related articles on the PHP Chinese website!