Creating custom packages in Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a package named "mathutils".

Go

package [1]

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

Amathutils

Bmain

Cfmt

Dutils

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'main' instead of the custom package name.

Forgetting the package declaration line.

The package keyword declares the package name. Here, it should be mathutils to create a custom package named "mathutils".

2fill in blank

medium

Complete the code to import the "fmt" package for printing.

Go

import [1]

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

A"mathutils"

B"os"

C"net/http"

D"fmt"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the quotes around the package name.

Importing the wrong package for printing.

The import statement includes external packages. To print output, you import "fmt".

3fill in blank

hard

Fix the error in the function declaration to make it exported from the package.

Go

func [1](a int, b int) int {
    return a + b
}

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

Asum

Badd

CAdd

DsumNumbers

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase function names for exported functions.

Not capitalizing the first letter of the function name.

In Go, to export a function from a package, its name must start with a capital letter. So Add is exported, while add is not.

4fill in blank

hard

Fill both blanks to create a map of word lengths for words longer than 3 characters.

Go

lengths := map[string]int{
    [1]: [2],
}

for _, word := range []string{"go", "code", "fun", "package"} {
    if len(word) > 3 {
        lengths[word] = len(word)
    }
}

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

A"code"

B4

C"word"

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names instead of string keys.

Using the word itself as a key without quotes.

The map key should be a string like "code", and the value should be 4, the length of "code".

5fill in blank

hard

Fill all three blanks to create a function that returns a map of uppercase words and their lengths for words longer than 3 characters.

Go

func [1](words []string) map[string]int {
    result := make(map[string]int)
    for _, [2] := range words {
        if len([2]) > 3 {
            result[strings.ToUpper([2])] = len([2])
        }
    }
    return result
}

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

AWordLengths

Bword

Cw

Dwords

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Not capitalizing the function name.

The function name is WordLengths. The loop variable is w, used consistently to check length and convert to uppercase.