Anonymous function in Go Language

Go language provides a special feature known as an anonymous function. An anonymous function is a function which doesn’t contain any name. It is useful when you want to create an inline function. In Go language, an anonymous function can form a closure. An anonymous function is also known as function literal.

Syntax:

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

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

Example:

Output:

Welcome! to GeeksforGeeks

Important Points:

• In Go language, you are allowed to assign an anonymous function to a variable. When you assign a function to a variable, then the type of the variable is of function type and you can call that variable like a function call as shown in the below example.

  Example:

  
  

  
  
  

  // Go program to illustrate // use of an anonymous function package main    import "fmt"    func main() {            // Assigning an anonymous     // function to a variable    value := func(){       fmt.Println("Welcome! to GeeksforGeeks")   }   value()      }

  Output:

  Welcome! to GeeksforGeeks

• You can also pass arguments in the anonymous function.

  Example:

  
  

  
  
  

  // Go program to pass arguments  // in the anonymous function package main    import "fmt"    func main() {            // Passing arguments in anonymous function   func(ele string){       fmt.Println(ele)   }("GeeksforGeeks")      }

  Output:

  GeeksforGeeks

• You can also pass an anonymous function as an argument into other function.

  Example:

  
  

  
  
  

  // Go program to pass an anonymous  // function as an argument into  // other 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) }

  Output:

  GeeksforGeeks

• You can also return an anonymous function from another function.

  Example:

  
  

  
  
  

  // Go program to illustrate // use of anonymous 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 ")) }

  Output:

  Welcome to GeeksforGeeks