Interface satisfaction in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an interface named Speaker.

Go

type Speaker interface {
	[1]()
}

Drag options to blanks, or click blank then click option'

AListen

BSpeak

CTalk

DRun

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name not related to speaking, like 'Run'.

Forgetting the parentheses after the method name.

The interface Speaker requires a method named Speak with no parameters.

2fill in blank

medium

Complete the code to make type Dog satisfy the Speaker interface by implementing Speak method.

Go

package main

import "fmt"

type Dog struct {}

func (d Dog) [1]() {
	fmt.Println("Woof!")
}

Drag options to blanks, or click blank then click option'

ASpeak

BTalk

CRun

DListen

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name like 'Talk' or 'Run'.

Missing the method receiver in the function.

The method Speak is required to satisfy the Speaker interface.

3fill in blank

hard

Fix the error in the code to make type Cat satisfy the Speaker interface.

Go

package main

import "fmt"

type Cat struct {}

func (c Cat) [1]() {
	fmt.Println("Meow!")
}

Drag options to blanks, or click blank then click option'

ASpeak

BListen

CRun

DTalk

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name.

Changing the method signature (parameters or return type).

The method Speak must have the same signature as in the interface. Here it returns nothing, which is acceptable if the interface method has no return.

4fill in blank

hard

Fill both blanks to declare an interface and a type that satisfies it.

Go

type [1] interface {
	[2]()
}

type Bird struct {}

func (b Bird) [2]() {
	fmt.Println("Tweet!")
}

Drag options to blanks, or click blank then click option'

ASinger

BSpeak

CTalk

DRunner

Attempts:

3 left

💡 Hint

Common Mistakes

Using different method names in interface and type.

Naming interface with a verb instead of a noun.

The interface is named Singer and requires a method Speak. The type Bird implements Speak to satisfy the interface.

5fill in blank

hard

Fill all three blanks to create a function that accepts any Speaker and calls its Speak method.

Go

func [1](s [2]) {
	s.[3]()
}

Drag options to blanks, or click blank then click option'

AMakeSound

BSpeaker

CSpeak

DAnimal

Attempts:

3 left

💡 Hint

Common Mistakes

Using a concrete type instead of the interface as parameter.

Calling a method name not defined in the interface.

The function MakeSound takes a parameter of type Speaker interface and calls its Speak method.