F # Tutorial: anonymous function (LAMBDA)

This time we're going to learn about lambda expressions. F # and C # have anonymous functions as well. But it feels better to call an anonymous function a lambda.

Try writing some code:

let　add　=　fun　x　y　->　x　+　y
printfn　"%A"　(add　1　3)

Here we define the Add function. This definition uses an anonymous function (takes out the x,y two parameters and returns the x+y result). Fun is the key word for anonymous functions.

The function definitions that you have before are:

Let add x y = x + y

This is an elliptical form. The difference is whether the parameter is in a lambda expression.

From the experience of C #, you can pass functions as arguments to other functions.

let　add　=　fun　x　y　->　x　+　y
let　hoge　func　=
　　　　 let　a　=　func　1　10
　　　　 printfn　"%A"　a
hoge　add　　//　将add作为参数传入hoge函数中

Yes, it does, the result is 11.

Of course, you can also try to pass the lambda expression directly into the previous function.

let　hoge　func　=
　　　　 let　a　=　func　1　10
　　　　 printfn　"%A"　a
hoge　(fun　x　y　->　x　+　y)　　//　直接传入lambda表达式

Lambda expressions are commonly used in c#3.0, which makes it less strange to use Lambda in F #.