Overview

Installation

brew install go

Configuration

Setup default workspace

mkdir ~/go
mkdir ~/go/src

Hello World Example

vi helloworld.go

package main
  
import (
  "fmt"
)

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

Run it

go run helloworld.go

Compile it

go build

Install it

go install

Functions 

Example showing error return

package main

import (
  "fmt"
  "error"
  "math"
)

func main() {
  result, err := sqrt(16)
  
  if err != nil {
    fmt.Println(err)
  } else {
    fmt.Println(result)
  }
}

func sqrt(x float64) (float64, error ) {
  if x < 0 {
    return 0, errors.New("Undefined for negative numbers")
  }
  return math.Sqrt(x), nil
} 

Structs/Types

package main
  
import (
  "fmt"
)

type person struct {
  name string
  age int
}

func main(){
  p:= person{name: "Jake", age: 23 }
  fmt.Println(p)
}

Commands

Variables

Variables are defined using the following syntax:

var <variablename> <type>

example:

var x int

All variables have a zero value and are pre-initialized to their zero value. For example, an int would have a zero value of 0 and a string would have a zero value of empty string "".

Initializing the variable at declaration time:

var x int = 5

Quick Syntax: infers type based on value.

x:=5

Example:

package main
  
import (
  "fmt"
)

func main(){
  var x int
  x = 5
  fmt.Println(x)
}

Structs

References