Anonymous function in Go Language

An anonymous function is a function that doesn’t have a name. It is useful when you want to create an inline function. In Go, an anonymous function can also form a closure. An anonymous function is also known as a function literal.

Example

package main
import "fmt"

func main() {
    // Anonymous function
    func() {
        fmt.Println("Welcome! to GeeksforGeeks")
    }()
}

Welcome! to GeeksforGeeks

Syntax:

func(parameter_list)(return_type) {
    // code..

    // Use return statement if return_type is given
    // if return_type is not given, then do not 
    // use return statement
    return
}()

Assigning to a Variable

You can assign an anonymous function to a variable. This variable can then be called like a regular function.

package main
import "fmt"

func main() {
    // Assigning an anonymous function to a variable
    value := func() {
        fmt.Println("Welcome! to GeeksforGeeks")
    }
    value()
}

Welcome! to GeeksforGeeks

Passing Arguments

Anonymous functions can accept arguments.

package main
import "fmt"

func main() {
    // Passing arguments in anonymous function
    func(ele string) {
        fmt.Println(ele)
    }("GeeksforGeeks")
}

GeeksforGeeks

Passing as Arguments

You can also pass an anonymous function as an argument to another function.

package main
import "fmt"

// Passing anonymous function as an argument
func GFG(i func(p, q string) string) {
    fmt.Println(i("Geeks", "for"))
}
func main() {
    value := func(p, q string) string {
        return p + q + "Geeks"
    }
    GFG(value)
}

GeeksforGeeks

Returning Anonymous Functions

You can return an anonymous function from another function.

package main
import "fmt"

// Returning anonymous function
func GFG() func(i, j string) string {
    myf := func(i, j string) string {
        return i + j + "GeeksforGeeks"
    }
    return myf
}

func main() {
    value := GFG()
    fmt.Println(value("Welcome ", "to "))
}

Welcome to GeeksforGeeks

Conclusion

Anonymous functions in Go are versatile and powerful. They can be used for creating inline functions, closures, and even for passing and returning functions. Understanding how to use them effectively can greatly enhance your programming in Go.