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66 lines
1.2 KiB
Markdown
66 lines
1.2 KiB
Markdown
---
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date: 20200826
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id: 3123184d-c919-4cf6-8339-3f9b8ca5a1db
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title: Golang Packages
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---
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# Basics
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Every Go program is made up of packages. Programs start running in
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package \`main\`.
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By convention the pacckage name is the same as the last element of the
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import path. For instance, the \`math/rand\` package comprises files
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that begin with the statement \`package rand\`.
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``` go
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package main
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import (
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"fmt"
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"math/rand"
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)
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func main() {
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fmt.Println("My favorite number is", rand.Intn(10))
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}
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```
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# Imports
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It's best practice to convert multiple import statements to a "factored"
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import statement:
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``` go
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package main
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import "fmt"
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import "math"
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func main() {
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fmt.Printf("This uses multiple import statements\n")
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fmt.Printf("Now you have %g problems.\n", math.Sqrt(7))
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}
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```
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should be
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``` go
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package main
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import (
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"fmt"
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"math"
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)
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func main() {
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fmt.Printf("This uses a parenthesized \"factored\" import statement\n")
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fmt.Printf("Now you have %g problems.\n", math.Sqrt(7))
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}
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```
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# Exported names
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In Go, a name is exported if it begins with a capital letter. When
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importing a package, you can refer only to its exported names. Any
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"unexported" names are not accessible from outside the package.
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