Running Go Programs

Building and Running Go Code

To run Go code, you need to do the following:

1. Download Go from https://golang.org/
2. Create a source code directory and input your Go code in there, with extension .go
3. Ways to run code
   1. Running one Go file: two ways
      • Use go build <filename> then run ./<filename> to run Go executable
      • Use go run <filename> to build and run code in one command
   2. Running a Go source directory
      1. Be in the directory one above the Go source directory
      2. Run go build -o <output-executable> <source-directory>, in which <output-exectuable> is your custom name of the Go executable
      3. Run ./<output-executable> <args>, in which <args> are potential input arguments to executable

Hello World

Sample code link: (https://repl.it/@jjoco/go-hello-world)

To create a "Hello World" program, you need a main function, like other C-like languages. Take the following example:

package main

import "fmt"

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

Notes

• The first statement in a Go source file must be package name. Executable commands must always use package main.
• Use fmt package in order to print out strings to the console. Here are some important functions:
  • fmt.Println(... args) : prints a list of variables to STDOUT with default formatting and inserts spaces between the variables and appends a new line at the end.
  • fmt.Printf(stringFormat, fields) : allows you to specify the formatting using a format template