Go 101

FreeCodeCamp.org https://www.youtube.com/watch?v=YS4e4q9oBaU

Go (golang) - golang.org

Characteristics of Go

• Strong and statically typed
• Excellent community
• Key features
  • Simplicity
  • Fast compile times
  • Garbage collected (still you can manage your memory)
  • Built-in concurrency
  • Compile to standalone binaries

Variables

• Variable declaration

var foo int
var foo int = 42
foo := 42

• Can't redeclare variables, but can shadow them

• All variables must be used

• Visibility

  • lower case first letter for package scope
  • upper case first letter to export
  • no private scope

• Naming conventions

  • HighCamelCase or lowerCamelCase
  • Capitalize acronyms (HTTP, URL)

• Type conversion

  • destinationType (variable)
  • use strconv package for strings
  • no implicit type conversion in Go

Go Global Variables

Exporting to .bashrc, .zshrc, etc.

export GOROOT=/usr/local/go
export PATH=$PATH:$GOROOT/bin

# Create this folder
export GOPATH=$HOME/golib
export PATH=$PATH:$GOPATH/bin

Go auto-completion

go get github.com/nsf/gocode

Primitive Types

• Numeric types
  • Integers
    • Signed Integers
    • int type has varying size, but min 32 bits
    • int8 through int64
  • Unsigned integers
    • 8 bit (byte or uint8) through uint32
  • Arithmetic operations
    • Addition, subtraction, multiplication, division, remainder
  • Bitwise operations
    • and (&) or (|), xor(^), and not (&^)
  • Zero value is 0
  • Can't mix types in same family (e.g. uint16 + uint32 = error)
  • Floating points numbers
    • Follows IEEE-754 standard
    • Zero value is 0
    • 32 and 64 bit versions
    • Literal styles
      • Decimal (3.14)
      • Exponential (13e18 or 2E10)
      • Mixed (13.7e12)
    • Arithmetic operations
      • Addition, subtraction, multiplication, division
  • Complex numbers
    • Zero value is (0+0i)
    • 64 and 128 bit versions
    • Built-in functions
      • complex - make complex number from two floats
      • real - get real part as float
      • imag - get imaginary part as float
    • Arithmetic operations
      • Addition, subtraction, multiplication, division
  • Text types
    • Strings
      • UTF-8
      • Immutable
      • Can be concatenated with plus (+) operator
      • Can be converted to []byte
    • Rune
      • UTF-32
      • Alias for int32
      • Special methods normally required to process
        • e.g. strings.Reader#ReadRune