What is a Package?

A package in Go is a way to organize and group related code together. Think of it as a folder that contains functions, variables, and types that work together to accomplish a specific purpose.

Every Go file must belong to a package, declared at the very top with the package keyword. The most important package you'll encounter is package main, which is special because it tells Go that this is an executable program with a main function as the entry point.

package main

import "fmt"

func main() {
    fmt.Println("Hello, World!")
}

To use code from other packages, you need to import them. In the example above, we import the fmt package, which provides formatting and printing functions. The fmt package is part of Go's standard library and comes built-in with the language.

Packages serve two main purposes: they help organize your code into logical groups and allow you to reuse code across different programs. This makes your programs more maintainable and prevents you from writing the same code multiple times.