My first steps in Golang

Course organized by Women Who Go Curitiba available on this Gitbook.

The Learn-Go-With-Test folder contains code from the Learn Go With Test gitbook.

Running the programs

If you don't have Go installed, you can run these code on The Go Playground. With Go instaled in your machine, you can enter go run SOURCE_FILE_NAME in the terminal.

What I've used so far

Each directory in this repo is a module of the course, containing my notes from the lessons and the activities. Here I'll try to summarize other important points asides the content directly in the modules:

Package

Every Go file will start with the reserved word package followed by the name of the package that is written on your file.

package main

is used to compile the file as an executable.

Imports

After naming your package, you can import packages that will be used in your code.

import "fmt"

is a package for formatting input and output.

func main()

Entry point of an executable.

func main() {
    // code your program will run
}

Declaring variables

There are two ways to declare variables in Go: using the reserved word var, or the short declaration operator :=.

When using var you can assign an initial value to an identifier (if you don't it will be initialized with its zero value). You can also declare the data type. If you don't, it will be inferred. If the variable is declared outside the scope of a function, it must be declared with var.

// basic syntax
var VARIABLE_NAME [TYPE] [= INITIAL_VALUE]

// example
var name string = "João"
var name string // initialized as ""
var name = "João" // type string is inferred

When using := the type is always inferred and the initial value must be assigned.

name := "João"

You can declare more than one variables at the same time.

var name, favoriteTeam string = "João", "Fluminense"

Pointers

You can pass a reference to a variable (instead of the value, passed by default) using a pointer.

var someVariable int = "some value"
var pointer *int = &someVariable // this will access someVariable's address in memory
// to access someVariable's value using pointer, use * (*pointer) to dereference

If a pointer is declared to a type but no value is passed (), its zero value is nil.

Pointers to structs don't need to be dereferenced, go does this automatically.

func (s *SomeStruct) SomeMethod() string{
    return s.content // could be (*s).content but the dereference is inferred.
}

jpgsaraceni/Lets-Go