Packages and imports

Go organizes code into packages—one directory, one package (usually). Import paths use module paths like github.com/org/repo/pkg. The playground uses a single main package; locally you split code across files in the same package.

Import rules

import "fmt"
import (
    "errors"
    "strings"
)

Unused imports fail compilation. Dot imports (. "fmt") and blank imports (_ "image/png") exist for special cases—avoid dot imports in application code.

Visibility

Exported identifiers start with an uppercase letter within a package. Package name is typically the last element of the import path—short, lowercase, no underscores.

Important interview questions and answers

1. Q: How does Go export symbols?
   A: Uppercase first letter exports from the package; lowercase stays internal.
2. Q: init function?
   A: Package-level func init() runs before main—use for registration or setup, not heavy logic.

Self-check

1. What happens with an unused import?
2. How do you make a type visible to other packages?

Tip: Uppercase exports symbols across packages—fmt.Println is exported; unexported helpers stay lowercase within the package.