Go Start | Table O Contents

The Go language infers the type of static variable created …

• Go Start | Table O Contents
  • Visual Studio Code
    • Go Version
    • Bash Profile
    • Check It
    • Go Commands
  • Main dot go
    • The Go file format
    • Execution
    • Change Directories
  • Go-static operator
    • Consolidation
    • Demonstration
  • Last Subtitle
  • Support
    • Patreon

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Visual Studio Code

Hint. Create a new My_GO directory from the Finder in Mac Os High Sierra at the location of your choice.

Now, fire up a copy of your favorite IDE or text editor.

Go Version

File, Open your new My_GO directory in Visual Studio Code.

From the View, Integrated Terminal in Visual Studio Code …

• Type the go version command at the local command prompt $, as follows:

go version

Returns,

go version go1.9.2 darwin/amd64

Bash Profile

In the dot bash underscore profile file .bash_profile of your home directory …

• Add a statement under your Symlinks subheading designating the path to your new My_GO directory

• By exporting your new settings for the GOPATH variable, as follows:

# Symlinks
#
# Add symlink to GOPATH variable
export GOPATH=$HOME/documents/My_GO
# Finished adapting your PATH environment variable
#

Note. The Go program will search for your files to execute following the path established via the GOPATH variable

Check It

1. Restart your Terminal window by first clicking the Kill Terminal icon located in the upper right-hand corner of the View Terminal window in Visual Studio Code

2. Next, select File, View Terminal once again to reestablish the View Terminal window

In order to verify the new path to your My_GO directory …

• Use the Go env command at the local My_GO prompt $ to check for path accuracy by piping the result through grep

env | grep GOPATH

Returns,

GOPATH=/Users/yourHomeDirectory/documents/My_GO

Note. The previous $HOME entry in bash corresponds to the home directory of your development machine.

Go Commands

Other commands available in Go are listed below using the following one-word code statement at the local Terminal prompt $, as follows:

go

Returns,

Note. The columns in the above table are set to be centered via Kramdown.

Therefore, both the title row and the data rows should all display as centered within their respective columns.

Main dot go

Your main dot go file should reside in the subdirectory of your instance under the src subdirectory of your My_GO directory.

Note. To move down a level .. using the bash change directory cd command, run the following command from your local Terminal $ prompt, as follows:

cd ..

The Go file format

The Go file format starts with a package main statement and is followed by your import statement, if any, and your main function func main, as follows:

package main

import (
    "fmt"
)

// Original main function given
func main() {
    fmt.Printf("Hello there, World!\n")
}

// Note. You may declare and assign static variables regular way in Go ( var, name, type ), as follow:

func main() {
    // Declare and assign variables
    var message string = (`Hello there, World!`)
    var newline string = ("\n")

    // Declare methods
    fmt.Printf(message + newline)
}

Execution

Create the following three subdirectories inside your My_GO directory …

1. bin

2. pkg

3. src

Under src place your *main dot go** program inside a hello subdirectory

Change Directories

Invoke the bash change directory cd command

• From the local Terminal prompt $ of your My_GO directory

• cd from your My_GO directory to the src subdirectory, as follows:

cd src

Next, cd once again from the src subdirectory to the hello subdirectory, as follows:

cd hello

From the hello subdirectory of your src subdirectory ( within your My_GO directory ) …

• Run the following command from the local Terminal prompt $ to execute your program

go run main.go

Returns,

Hello there, World!

Go-static operator

The Go-static operator := condenses the declaration and assignment steps when creating variables, constants, and other features of the Go programming language.

Recall from above the regular way declaration and assignment of the message and newline static variables, both of the string type, as follows:

// Declare and assign variables
    var message string = (`Hello there, World!`)
    var newline string = ("\n")

Note. The declaration and assignment steps are separated by a single = sign when declaring and assigning a static variable regular way in Go.

Consolidation

The Go-static operator := allows for the consolidation of the declaration and assignment steps of a static variable, as follows:

// Create variables using the Go-static operator
    message := `Hello there, World!`
    newline := "\n"

Note. You can even kiss the parenthesis (...) goodbye, as well, when creating a variable using the Go-static operator :=

Demonstration

Let’s now plug that new-fangled set of static variables created with the Go-static operator := into our main func, run the program, and check the results, as follows:

package main

import (
    "fmt"
)

func main() {
    // Create variables using the Go-static operator
    message := `Hello there, World!`
    newline := "\n"

    // Declare methods
    fmt.Printf(message + newline)
}

Returns,

Hello there, World!

Note. The Go language infers the type of static variable created from the input given by the programmer on the right-side of the Go-static operator :=

Last Subtitle

More to come …

Note. The above synopsis was derived from an article written by Mark Lewin [1].

1. Code lines courtesy of Go Succinctly by Mark Lewin. Published by © 2017 Syncfusion.com.

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