Public and Private Functions

Visibility is on a per package level only.

A package is the smallest unit of private encap­sulation in Go.

All identifiers defined within a package are visible throughout that package. When importing a package you can access only its exported identifiers.

An identifier is exported if it begins with a capital letter. If an identifier starts with a lower case letter, it can only be accessed from within the package.

Example

Defining the functions Sum, Divide and Add of the expressions.go starting with capital letters makes them accessible in main.go.

// Sum : sums up slice values provided as argument.
func Sum(values ...float64) float64 {

}

Usage

Run the program with the command:

go run main.go expressions.go