go

🐨 Go lang Study Repository.

00 - Basic

A little bit of the basics.!

What have learned?

• Programs in go are made up of packages.
• Module imports are done using the import key and can be factored using parentheses () to group multiple imports.
• Named exports are done using campitalyzed words 'SameExample',
• Functions take one or more arguments where the type follows the argument name!
• When arguments share the same type, I can omit all and preserve only the last x int, y int for x, y int.
• Function can return one or several results.
• Variables can be declared using the var key eg var nameVariable type.
• Variables can be initialized using var nameVariable = value. In this case the type can be omitted as the variable will take the type of the initiator.
• Inside a function I can use short variables using :=, but outside the functions I must use the var key.
• The basic types are bool, string, byte, rune, float32, float64.
• Zero values ​​are, 0 for numbers, false for booleans and "" for strings.
• When a variable is declared without specifying the type, the type is defined according to the assigned value.
• Constants are declared using the const key and values ​​cannot be assigned using :=.
• Go has only one type of loop, the for.
• Reference

01 - Hello World

Hello world in GO!

What have learned?

• Create a module using the go init command.
• Declare a package.
• Import standard packages.
• Importing external packages.
• Synchronize dependencies using the go mod tidy command.
• Reference | Commit

02 - First module

Creating a module!

What have learned?

• Declaring a function, as well as the type of parameter and return.
• I learned that functions with a capital initial can be called by a function that is not in the same package.
• I learned how to declare a variable and assign the value in one line using :=.
• Formatting a string using the Sprintf function.
• Reference | Commit

03 - Using module

Import a local module!

What have learned?

• Import a local module.
• Use the go mod edit -replace module=directory command to reference a local module.
• Reference | Commit

04 - Handling errors

Validations and error handling!

What have learned?

• How a function can return multiple values.
• Use the errors module to throw exceptions.
• Use the log module to display errors in the terminal.
• Assign value to a variable already declared using =.
• Reference | Commit

05 - Random values

Get random values based on a condition!

What have learned?

• The use of the init function to execute functions at startup.
• Declare a slice/array.
• Get the size of a data using the len function.
• Use the Seed function of the rand module to initialize the seeds on each run.
• Use the Intn function of the rand module to generate a random number within the specified maximum size.
• Reference | Commit

06 - Maps, Slices and Iteration

Iterate a slice and populate a map!

What have learned?

• Declare a map and initialize using the make function.
• Use the for-range loop to iterate over a map/slice/array.
• Use the blank _ identifier to ignore the value.
• Use a generic type with interface {}.
• Reference | Commit

06 - Unit test

Unitary tests!

What have learned?

• A test file must be named with the suffix _test.go.
• The test function must start with Test name.
• The test function must take a single t *testing.T argument providing all the necessary functions for the test.
• Use go test command to run.
• Use the testing module.
• Use regexp module to work with regex.
• Reference | Commit