Challenge 01 - Type Assertions in Go

In this challenge, we are going to become familiar with the concept of Type Assertions in Go!

Preface

If you are new to the language, then type assertions are a concept that can sometimes trip you up and appear a little tricky at first, but after overcoming the syntax it becomes far easier to understand.

Through using type assertions, we can retrieve the dynamic value of an interface. For example:

var myName interface{} = "Elliot"

name := myName.(string)
fmt.Println(name)

In this example, we have an interface which has a dynamic value of “Elliot”. We can then use a type assertion to retrieve this dynamic value and use the value just like we would any other string value in Go.

Challenge

In this challenge, we are going to define a function that is called GetDeveloper which will take in 2 interface{} arguments.

Within this function, you will have to declare a new Developer instance and use type assertion to populate the values correctly before then returning this new Developer instance.

package main

import (
  "fmt"
)

// Developer struct
type Developer struct {
  Name string
  Age int
}

func GetDeveloper(name interface{}, age interface{}) Developer {
  var dev Developer
  dev.Name = name.(string)
  dev.Age = age.(int)
  return dev
}

func main() {
  fmt.Println("Hello World")

  var name interface{} = "Elliot"
  var age interface{} = 26

  dynamicDev := GetDeveloper(name, age)
  fmt.Println(dynamicDev.Name)
}

Further Reading

• Go Interfaces Tutorial

Other Challenges