Doc Utilities

In order to understand the different functions and methods, go provides multiple sources of documentation:

• go doc command, that works as man for go functions and packages (e.g go doc fmt.Printf)
• godoc app that starts a web server with the rendered docs (e.g godoc -http :8080)
• Online docs

Syntax

• Go programs don’t use semicolons to end statements. Instead the compiler detects new lines.
• Case sensitive (Capital first letter means a field/method is exported or public)

builtin Package

• Is included by default
• Among others has:
  • panic(): To display and error and exit the program
  • len(): To determine length of things (arrays, strings, maps, etc)
• It also includes the basic types
• More info in the docs

Types

Basic types include:

bool
string
uint, uint8, uint16, uint32, uint64 //Unsigned integer
int, int8, int16, int32, int64 // Integer, int can vary on the machine architecture (32 or 64 bits)
byte //Alias for int8
rune //Alias for int32, represents an unicode code point
float32, float64
complex64, complex128 //Complex numbers (0 + 2i)

More complex types include:

• Arrays
• Slices (Similar to List in Java, variable size array)
• Maps
• Struct
• Function (Go allows for functional programming)
• Interface
• Channel
• Pointer (Similar to C, a reference to memory)
• Custom Types

Declarations

Variables can be declared in different ways:

var x int //Initializes the variable in the zero value
var x int = 2 // Explicit declaration and assignment
var x = 2 //Type is inferred 
x := 2 //Shorthand for type inference - ONLY USABLE INSIDE FUNCTIONS SCOPE

At the same time constants, can be used (outside functions)

const Pi = 3.14
const (
    Pi = 3.14
    Wa = 3.68
    We = "AEIOU"
)