Vivek Anand Sharma
Slim Coder
GOLANG FOR ABSOLUTE BEGINNERS
AGENDA
- Introduction of Speaker
- Introduction of Golang
- Variables
- Primitives
- Contants
- Arrays And Slices
- Maps And Structs
- Control Flow
- Looping
- Defer , Panic And Recover
- Pointers
- Functions
- Methods
- Functions V/S Methods
- Interfaces
- Goroutines
- Channels
INTRODUCTION
OF SPEAKER
I'm Vivek
- Software Engineer at Trukkr
- Community Lead of Golang Pakistan.
- Communiy Manager of MWB
- Co-Founder of DevCreatives++.
- Founded 2 Top GitHub Organizations.
- Writing For 3 Publishers on Medium.
- Member of AWS and Linux Pakistan.
I'M ON THESE PLACES
I'M A.K.A SLIM CODER
IT'S ALL START WITH
IT'S ALL START WITH EM
LOSE YOURSELF
EMINEM
WHEN I'M GONE
MARSHAL
MY NAME IS
SLIM SHADY
SLIM IS ON THESE PLACES
IT'S ALL START WITH
WANT TO LEARN MORE
INTRODUCTION OF GOLANG
- Golang was created by 3 software engineer of Google namely Robert , Rob and Ken.
WHO CREATED GOLANG ?
- There was some limitation Google running into that's why they decide to create a new language.
- Before Golang , Google was using 3 languages i.e Python , Java and C/C++ but still there was some limitation with these languages.
WHY GOLANG ?
- Python was easy to use but slow at the same time because it is an interpreted language.
- Java was quick but its type system was complex for distrubing system.
- C/C++ was quick but its type system was complex for distrubing system and it have slow compiles times.
WHAT IS GOLANG ?
- Strong and Statically Typed
- Awesome Community
- Simplicity
- Fast Compiles Times
- Garbage Collected
- Built-In Concurrency
- Compile To Standalone Library
VARIABLES
VARIABLES
// 1st Way
var i int ;
i = 42 ;
// 2nd Way
var j int = 42 ;
// 3rd Way
k:= 42 ;PRIMITIVES
PRIMITIVES
// Boolean
n := 1 == 1
m := 2 == 3
var a bool = true
b := true
// Integer
c := 1
// Floating
e := 1.4543
// String
g := "hello"
h := "world"
// Complex
var i complex128 = 1 + 2i
var j complex128 = complex(1, 2)
b := 1+2i
b := complex(1,2)CONSTANTS
CONSTANTS
// Float
const b float32 = 2.4;
// String
const c string = "string constant";
// Boolean
const d bool = true;
// Integer
const a int = 5;
// Complex
const j complex128 = complex(1, 2);ARRAYS AND SLICES
ARRAYS AND SLICES
// One Dimentional Arrays (Pass By Value By Default)
grades := [3]int{1, 2, 3};
var students [3]string;
students[0] = "Vivek";
students[1] = "Fahad";
students[2] = "Darshan";
a := [...]string{"hello", "world"};
// Multi-Dimentional Arrays
var matrix1 = [3][3]int{[3]int{1, 2, 3}, [3]int{1, 2, 3}, [3]int{1, 2, 3}}
var matrix2 [3][3]int
matrix2[0] = [3]int{1, 2, 3}
matrix2[1] = [3]int{1, 2, 3}
matrix2[2] = [3]int{1, 2, 3}
// Slices (Pass By Reference By Default)
slicea := []int{1, 2, 3}
// Multi-Dimentional Slices
slicea := [][]int{{1,2,3},{1,2,3},{1,2,3}}MAP AND STRUCTS
MAP AND STRUCTS
// Map (Key Value) -> Pass By Reference
a := map[string]string{
"firstName": "Vivek",
"middleName": "Anand",
"lastName": "Sharma",
}
//Structs -> Pass By Value
type Doctor struct {
firstName string
middleName string
lastName string
}
aDoctor := Doctor{
firstName: "Vivek",
middleName: "Anand",
lastName: "Sharma",
}CONTROL FLOW
CONTROL FLOW
// IF statement
if true {
fmt.Println("The test is true")
}
// IF ELSE IF statement
guessB := 40
if guessB < 30 {
fmt.Println("Too Low")
} else if guessB > 30 {
fmt.Println("Too High")
} else {
fmt.Println("To Equal")
}
// SWITCH Statement
switch 2 {
case 1:
fmt.Println("Case 1")
case 2:
fmt.Println("Case 2")
default:
fmt.Println("Case Default")
}LOOPING
LOOPING
// For Loop
for i := 0; i < 5; i++ {
fmt.Println("Output")
}
// Infinite For Loop
for {
fmt.Println("Infinite Output")
}
DEFER, PANIC AND RECOVER
DEFER, PANIC AND RECOVER
// Defer
fmt.Println("start")
defer fmt.Println("middle")
fmt.Println("end")
// Panic
fmt.Println("start")
panic("Something bad happened")
fmt.Println("end")
// Defer , Panic and Recover
fmt.Println("start")
defer func() {
if err := recover(); err != nil {
fmt.Println("Error:", err)
}
}()
panic("something bad happened")
fmt.Println("end")POINTERS
POINTERS
// Pointers
var a int = 45
var b *int = &a
a = 25
fmt.Println(a, *b)FUNCTIONS
FUNCTIONS
func sayMessage(msg string, id int) {
fmt.Println("Message is : ", msg)
fmt.Println("Id is : ", id)
}
METHODS
METHODS
// Go program to illustrate the
// method with struct type receiver
package main
import "fmt"
// Author structure
type author struct {
name string
branch string
particles int
salary int
}
// Method with a receiver
// of author type
func (a author) show() {
fmt.Println("Author's Name: ", a.name)
fmt.Println("Branch Name: ", a.branch)
fmt.Println("Published articles: ", a.particles)
fmt.Println("Salary: ", a.salary)
}
// Main function
func main() {
// Initializing the values
// of the author structure
res := author{
name: "Sona",
branch: "CSE",
particles: 203,
salary: 34000,
}
// Calling the method
res.show()
} FUNCTIONS VS METHODS
FUNCTIONS V/S METHODS
// Function Syntax
func function_name(parameter_list)(return_type) {
// Code
}
// Method Syntax
func(reciever_name Type) method_name(parameter_list)(return_type){
// Code
}INTERFACES
INTERFACES
package main
import "fmt"
// Interface => Define Behaviour
type Shape interface {
Area() float64
}
// Struct
type Rect struct {
width float64
height float64
}
// Area Method
func (r Rect) Area() float64 {
return r.width * r.height
}
// Main Function
func main() {
var s Shape
s = Rect{5.0, 4.0}
fmt.Println("Area of Rectangle Is : ", s.Area())
}
GOROUTINES
GOROUTINES
package main
// Synchronous package
import (
"fmt"
"sync"
)
// Wait Group
var wg = sync.WaitGroup{}
// Main Function
func main() {
wg.Add(1)
go sayHello()
fmt.Println("Hello World 2");
wg.Wait()
}
// SayHello Function
func sayHello() {
fmt.Println("Hello World 1")
wg.Done()
}CHANNELS
CHANNELS
package main
import (
"fmt"
"sync"
)
var wg = sync.WaitGroup{}
func main() {
ch := make(chan int)
wg.Add(2)
go func() {
ch <- 42
wg.Done()
}()
go func() {
i := <-ch
fmt.Println(i)
wg.Done()
}()
wg.Wait()
}WANT TO LEARN MORE
You can find complete codebase on GitHub.
SUGGESTIONS
Don't forget to write your first server on GoLang by using this framework known as gin.
Don't forget to read this article.
Don't forget to install Golang on your system and run all programs which we tested on Golang playgroud.
READY TO JOIN GOLANG PAKISTAN
Don't forget to join Golang Pakistan Group on Facebook.
WANTS TO JOIN MENTORS WITHOUT BORDERS?
If yes! then don't forget to send me an email: vivek@mentorswithoutborders.net
WANTS TO JOIN LINUX PAKISTAN?
If yes! then don't forget to send me an email: vivek@linuxpakistan.org
Golang For Absolute Beginners - DSC UoS
By Vivek Anand Sharma
