Create a module

To create a Go module, you need to follow these steps:

Initialize a new module: Use the go mod init command to create a new module.
Create packages: Organize your code into packages.
Use the module: Import and use the packages within your module.

Here are detailed examples:

Step 1: Initialize a New Module

First, create a new directory for your project and navigate into it. Then, initialize the module.

mkdir mymodule
cd mymodule
go mod init github.com/username/mymodule

Step 2: Create Packages

Create a directory structure for your packages. For example, create two packages: math and stringutil.

mkdir -p math stringutil

Example: `math` Package

Create a file math/math.go:

package math

// Add adds two integers and returns the result.
func Add(a, b int) int {
    return a + b
}

Example: `stringutil` Package

Create a file stringutil/stringutil.go:

package stringutil

// Reverse returns the reverse of the given string.
func Reverse(s string) string {
    runes := []rune(s)
    for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
        runes[i], j = runes[j], runes[i]
    }
    return string(runes)
}

Step 3: Use the Module

Create a main.go file in the root directory to use the packages.

package main

import (
    "fmt"
    "github.com/username/mymodule/math"
    "github.com/username/mymodule/stringutil"
)

func main() {
    // Use the math package
    sum := math.Add(3, 4)
    fmt.Println("Sum:", sum)

    // Use the stringutil package
    reversed := stringutil.Reverse("hello")
    fmt.Println("Reversed:", reversed)
}

Step 4: Run the Program

Run the program using the go run command.

go run main.go

This will output:

Sum: 7
Reversed: olleh

By following these steps, you can create a Go module with multiple packages and use them in your project.

Last modified: 19 December 2024