learn-golang

Basic Concepts

1. Basic Introduction (Hello World)

Go is a programming language designed for simplicity and efficiency. Let's start by writing your first program: "Hello, World!"
Learn more about Go basics

package main  

import "fmt"  

func main() {  
    fmt.Println("Hello, World!")  
}  

Solo Tasks

1. Change the message to say "Hello, [Your Name]!"
2. Add another line that says "I am learning Go!"

---

2. Introduction to Data Types

Go has several basic data types: string, int, float64, and bool.
Learn more about Go data types

package main  

import "fmt"  

func main() {  
    var name string = "Alice"  
    var age int = 11  
    var height float64 = 4.5  
    var isLearning bool = true  

    fmt.Println("Name:", name)  
    fmt.Println("Age:", age)  
    fmt.Println("Height:", height)  
    fmt.Println("Is Learning Go:", isLearning)  
}  

Solo Tasks

1. Change the values of the variables to describe yourself.
2. Add a new variable for your favorite color and print it.
3. Try declaring a variable without specifying its type.

---

3. Introduction to If Statements

If statements allow your program to make decisions.
Learn more about if statements

package main  

import "fmt"  

func main() {  
    age := 11  

    if age < 13 {  
        fmt.Println("You are a child.")  
    } else {  
        fmt.Println("You are a teenager or older.")  
    }  
}  

Solo Tasks

1. Add a condition to check if age is between 13 and 19
2. Add a condituon to check if age is above 19
3. Add a condition to check if age is below 13
4. Add a conditon to check whether or not the age is even or odd

---

4. Using Command-Line Arguments

Command-line arguments allow you to pass information to your program when you run it.
Learn more about command-line arguments

package main  

import (  
    "fmt"  
    "os"  
)  

func main() {  
    if len(os.Args) < 2 {  
        fmt.Println("Usage: go run main.go [your name]")  
        return  
    }  

    name := os.Args[1]  
    fmt.Printf("Hello, %s!\n", name)  
    fmt.Println("I am learning Go!")  
}  

Solo Tasks

1. Modify the program to accept a second argument for your age and print it.
2. Add a condition to check if no arguments are provided and display a helpful message.
3. Experiment with passing multiple arguments and printing them all.

---

5. Introduction to Functions

Functions are reusable blocks of code. They help organize your program.
Learn more about functions

package main  

import "fmt"  

func greet(name string) {  
    fmt.Println("Hello,", name)  
}  

func main() {  
    greet("Alice")  
}  

Solo Tasks

1. Modify the greet function to include the person's age.
2. Write a new function that adds two numbers and prints the result.
3. Call your new function in the main function.

---

6. Introduction to Switch Statements

Switch statements allow you to simplify multiple conditional checks.
Learn more about switch statements

package main  

import "fmt"  

func main() {  
    day := "Monday"  

    switch day {  
    case "Monday":  
        fmt.Println("Start of the work week.")  
    case "Friday":  
        fmt.Println("Almost the weekend!")  
    case "Saturday", "Sunday":  
        fmt.Println("It's the weekend!")  
    default:  
        fmt.Println("It's a regular weekday.")  
    }  
}  

Solo Tasks

1. Modify the program to include a case for your favorite day of the week.
2. Add a case that checks for multiple days (e.g., "Tuesday" and "Thursday").
3. Write a program that uses a switch statement to categorize a number as positive, negative, or zero.

---

7. Introduction to Loops

Loops let you repeat actions in your program.
Learn more about loops

package main  

import "fmt"  

func main() {  
    for i := 1; i <= 5; i++ {  
        fmt.Println("Count:", i)  
    }  
}  

Solo Tasks

1. Write a loop that prints numbers from 10 to 1.
2. Create a loop that prints all even numbers between 1 and 20.
3. Use a while-like loop (a for loop with a condition) to keep asking for input until the user types "stop".

---

8. Introduction to Tests

Tests ensure your code works as expected.
Learn more about testing

package main  

func add(a, b int) int {  
    return a + b  
}  

Test File:

package main  

import "testing"  

func TestAdd(t *testing.T) {  
    result := add(2, 3)  
    if result != 5 {  
        t.Errorf("Expected 5, got %d", result)  
    }  
}  

Solo Tasks

1. Write a test for a function that multiplies two numbers.
2. Add a test for a function that checks if a number is even.
3. Run your tests and fix any errors.

---

9. CLI Calculator

Task

Create a command-line calculator that:

1. Asks the user for two numbers.
2. Asks the user for an operation (+, -, *, /).
3. Performs the operation and prints the result.
4. Repeats until the user types "exit".

---

Advanced Concepts

1. Introduction to Structs and Methods

Go does not have classes, but you can use structs and methods to achieve similar functionality.
Learn more about structs and methods

package main  

import "fmt"  

type Person struct {  
    Name string  
    Age  int  
}  

func (p Person) Greet() {  
    fmt.Printf("Hello, my name is %s and I am %d years old.\n", p.Name, p.Age)  
}  

func main() {  
    person := Person{Name: "Alice", Age: 11}  
    person.Greet()  
}  

Solo Tasks

1. Add a new field to the Person struct for the person's favorite hobby.
2. Write a method that prints the person's hobby.
3. Create multiple Person instances and call their methods.

---

2. Creating, Reading, and Writing a File

Go provides tools to work with files for reading and writing data.
Learn more about file handling

package main  

import (  
    "fmt"  
    "os"  
)  

func main() {  
    file, err := os.Create("example.txt")  
    if err != nil {  
        fmt.Println("Error creating file:", err)  
        return  
    }  
    defer file.Close()  

    file.WriteString("Hello, Go!")  
    fmt.Println("File written successfully.")  
}  

Solo Tasks

1. Modify the program to read the content of the file and print it.
2. Write a program that appends text to an existing file.
3. Handle errors gracefully when the file does not exist.

---

3. Basic Web Server Functionality

Go makes it easy to create web servers using the net/http package.
Learn more about web servers

package main  

import (  
    "fmt"  
    "net/http"  
)  

func handler(w http.ResponseWriter, r *http.Request) {  
    fmt.Fprintln(w, "Welcome to my web server!")  
}  

func main() {  
    http.HandleFunc("/", handler)  
    fmt.Println("Starting server on :8080...")  
    http.ListenAndServe(":8080", nil)  
}  

Solo Tasks

1. Modify the handler to display a personalized message based on a query parameter (e.g., ?name=Alice).
2. Add a new route that displays the current date and time.
3. Create a simple HTML page and serve it using your web server.

---

4. Advanced Web Server Functionality (HTML + CSS)

You can serve HTML and CSS files to create more interactive web pages.
Learn more about serving files

package main  

import (  
    "net/http"  
)  

func main() {  
    fs := http.FileServer(http.Dir("./static"))  
    http.Handle("/", fs)  

    http.ListenAndServe(":8080", nil)  
}  

Solo Tasks

1. Create a static folder with an index.html file and serve it.
2. Add a CSS file to style your HTML page.
3. Create a form in your HTML page and handle its submission in Go.

---

5. Introduction to Interfaces

Interfaces define a set of methods that a type must implement.
Learn more about interfaces

package main  

import "fmt"  

type Shape interface {  
    Area() float64  
}  

type Circle struct {  
    Radius float64  
}  

func (c Circle) Area() float64 {  
    return 3.14 * c.Radius * c.Radius  
}  

func main() {  
    var s Shape = Circle{Radius: 5}  
    fmt.Println("Area of the circle:", s.Area())  
}  

Solo Tasks

1. Create a Rectangle struct and implement the Shape interface.
2. Write a function that takes a Shape and prints its area.
3. Add another method to the Shape interface and implement it for both Circle and Rectangle.