function-as-parameter.go

package main

import "fmt"

// we can put like this in here
func greetMorning(name string, filter func(string) string) string {
	return "Good Morning " + filter(name)
}

// or we can put type definition as a alias and put in parameter
type Filter func(string) string

func greetMorningAlias(name string, filter Filter) string {
	return "Good Morning " + filter(name)
}

// notice that the function must have same signature in parameter above
func filter(name string) string {
	if name == "kotor" {
		return "****"
	} else {
		return name
	}
}

func main() {
	// function as parameter
	// we can pass functions as parameters to other functions
	result := greetMorning("kasar", filter)
	fmt.Println(result)

	result = greetMorning("Luthfi", filter)
	fmt.Println(result)

	// with type declaration as alias
	result2 := greetMorningAlias("kotor", filter)
	fmt.Println(result2)

	result2 = greetMorningAlias("Akbar", filter)
	fmt.Println(result2)
}