go/01-basics/calculator.go

@@ -4,57 +4,71 @@ import (
 	"fmt"
 )
  
+const (
+	opAdd      = "add"
+	opSubtract = "subtract"
+	opMultiply = "multiply"
+	opDivide   = "divide"
+	opExit     = "exit"
+)
+ 
+var result float64
+ 
+func add(a, b float64) {
+	result = a + b
+}
+func multiply(a, b float64) {
+	result = a * b
+}
+func subtract(a, b float64) {
+	result = a - b
+}
+func divide(a, b float64) {
+	result = a / b
+}
+ 
 func main() {
-	const (
+	var x float64
-		add      = "add"
+	var y float64
-		subtract = "subtract"
-		multiply = "multiply"
-		divide   = "divide"
-		exit     = "exit"
-	)
 
 	//TODO: implement according to README.md 
-	fmt.Println("Welcome to the Simple Calculator!")
-	for {
-		var operation string
-		fmt.Print("\nEnter operation (add, subtract, multiply, divide, exit): ")
-		fmt.Scan(&operation)
 
-		//the following code just demonstrates how to use fmt.Scan
+	//the following code just demonstrates how to use fmt.Scan
-		if operation == exit {
-			fmt.Println("Goodbye!")
-			break
-		}
 
+		for {
+		fmt.Print("What would you like to do? (add|subtract|divide|multiply|exit)")
 		var str string
-		fmt.Print("Please enter a string: ")
 		fmt.Scan(&str)
-		var num1, num2 float64
+		if str == opExit {
-		fmt.Print("Enter the first number: ")
+			break
-		fmt.Scan(&num1)
+		} else {
-		fmt.Print("Enter the second number: ")
-		fmt.Scan(&num2)
  
-		var x float64
+			fmt.Print("Please enter a float: ")
-		fmt.Print("Please enter a float: ")
+			fmt.Scan(&x)
-		fmt.Scan(&x)
  
-		fmt.Printf("You entered '%s' and %f\n", str, x)
+			fmt.Print("Please enter a float: ")
-		switch operation {
+			fmt.Scan(&y)
-		case add:
+ 
-			fmt.Printf("Result: %.2f\n", num1+num2)
+			switch str {
-		case subtract:
+			case opAdd:
-			fmt.Printf("Result: %.2f\n", num1-num2)
+				add(x, y)
-		case multiply:
+				fmt.Println(result)
-			fmt.Printf("Result: %.2f\n", num1*num2)
+			case opMultiply:
-		case divide:
+				multiply(x, y)
-			if num2 == 0 {
+				fmt.Println(result)
-				fmt.Println("Error: Division by zero is not allowed!")
+			case opDivide:
-			} else {
+				if y == 0 {
-				fmt.Printf("Result: %.2f\n", num1/num2)
+					fmt.Println("Division by 0 is not possible")
+					continue
+				}
+				divide(x, y)
+				fmt.Println(result)
+			case opSubtract:
+				subtract(x, y)
+				fmt.Println(result)
+			default:
+				fmt.Println("Unknown operation")
 			}
-		default:
-			fmt.Println("Invalid operation. Please try again.")
 		}
 	}
 }

go/01-basics/calculatorEigen.go

@@ -1,74 +0,0 @@
-package main
-
-import (
-	"fmt"
-)
-
-const (
-	opAdd      = "add"
-	opSubtract = "subtract"
-	opMultiply = "multiply"
-	opDivide   = "divide"
-	opExit     = "exit"
-)
-
-var result float64
-
-func add(a, b float64) {
-	result = a + b
-}
-func multiply(a, b float64) {
-	result = a * b
-}
-func subtract(a, b float64) {
-	result = a - b
-}
-func divide(a, b float64) {
-	result = a / b
-}
-
-func main() {
-	var x float64
-	var y float64
-
-	//TODO: implement according to README.md
-
-	//the following code just demonstrates how to use fmt.Scan
-
-	for {
-		fmt.Print("What would you like to do? (add|subtract|divide|multiply|exit)")
-		var str string
-		fmt.Scan(&str)
-		if str == opExit {
-			break
-		} else {
-
-			fmt.Print("Please enter a float: ")
-			fmt.Scan(&x)
-
-			fmt.Print("Please enter a float: ")
-			fmt.Scan(&y)
-
-			switch str {
-			case opAdd:
-				add(x, y)
-				fmt.Println(result)
-			case opMultiply:
-				multiply(x, y)
-				fmt.Println(result)
-			case opDivide:
-				if y == 0 {
-					fmt.Println("Division by 0 is not possible")
-					continue
-				}
-				divide(x, y)
-				fmt.Println(result)
-			case opSubtract:
-				subtract(x, y)
-				fmt.Println(result)
-			default:
-				fmt.Println("Unknown operation")
-			}
-		}
-	}
-}

go/01-basics/inventory.go

@@ -1,110 +1,65 @@
-	package main
+package main
 
-import "fmt"
+import (
-
+	"fmt"
-type Category int
-
-const (
-	Electronics Category = iota
-	Groceries
-	Clothes
 )
 
-func (c Category) String() string {
-	switch c {
-	case Electronics:
-		return "Electronics"
-	case Groceries:
-		return "Groceries"
-	case Clothes:
-		return "Clothes"
-	default:
-		return "Unknown"
-	}
-}
-
-// Struct for product details
 type Product struct {
 	Name     string
 	Price    float64
 	Quantity int
-	Category string //TODO: use enum instead
+	Category int //TODO: use enum instead
-	Category Category
 }
 
+const(
+	Electronics int = iota
+	Groceries
+	Clothes
+)
+
 func addProduct(inventory *[]Product, name string, price float64, quantity int, category string) {
 	//TODO: implement
-// Add a new product to the inventory
+	var l int = inventory.len
-func addProduct(inventory *[]Product, name string, price float64, quantity int, category Category) {
+	inventory = append(inventory, name, price, quantity, category)
-	// Check if the product already exists in the inventory
-	for _, product := range *inventory {
-		if product.Name == name {
-			fmt.Println("Product already exists.")
-			return
-		}
-	}
-	// Add the new product
-	*inventory = append(*inventory, Product{
-		Name:     name,
-		Price:    price,
-		Quantity: quantity,
-		Category: category,
-	})
-	fmt.Printf("Added product: %s\n", name)
 }
 
-// Remove a product from the inventory
 func removeProduct(inventory *[]Product, name string) {
 	//TODO: implement
-	for i, product := range *inventory {
+	inventory = inventory.delete(name)
-		if product.Name == name {
-			*inventory = append((*inventory)[:i], (*inventory)[i+1:]...)
-			fmt.Printf("Removed product: %s\n", name)
-			return
-		}
-	}
-	fmt.Println("Product not found.")
 }
 
-// Update the quantity of a product
 func updateQuantity(inventory *[]Product, name string, newQuantity int) {
 	//TODO: implement
-	for i, product := range *inventory {
+	sliceInventory[name].quantity = newQuantity;
-		if product.Name == name {
-			(*inventory)[i].Quantity = newQuantity
-			fmt.Printf("Updated quantity for %s: New Quantity = %d\n", name, newQuantity)
-			return
-		}
-	}
-	fmt.Println("Product not found.")
 }
 
-// Display the inventory
 func displayInventory(inventory []Product) {
 	//TODO: implement
-	fmt.Println("Inventory:")
+	for _, p := range sliceInventory{
-	for _, product := range inventory {
+		fmt.Println(karte(sliceInventory[p]))
-		fmt.Printf("%s - %s (Price: $%.2f, Quantity: %d)\n",
-			product.Name, product.Category, product.Price, product.Quantity)
 	}
 }
 
 func main() {
-	// Initialize inventory
 	inventory := []Product{
-		{Name: "Laptop", Price: 1000, Quantity: 5, Category: "Electronics"},
-		{Name: "Apples", Price: 2, Quantity: 50, Category: "Groceries"},
-		{Name: "T-shirt", Price: 10, Quantity: 20, Category: "Clothes"},
 		{Name: "Laptop", Price: 1000, Quantity: 5, Category: Electronics},
 		{Name: "Apples", Price: 2, Quantity: 50, Category: Groceries},
 		{Name: "T-shirt", Price: 10, Quantity: 20, Category: Clothes},
 	}
+	var arrInventory = [3]string{"Laptop", "Apples", "T-shirt"} 
+	var sliceInventory = arrInventory[:]
+
+	karte := map[string]Product{
+		"Laptop": {Name: "Laptop", Price: 1000, Quantity: 5, Category: Electronics}, 
+		"Apples": {Name: "Apples", Price: 2, Quantity: 50, Category: Groceries},
+		"T-shirt": {Name: "T-shirt", Price: 10, Quantity: 20, Category: Clothes},
+	
+	}
 
 	// Display initial inventory
 	displayInventory(inventory)
 
 	// Add a new product
-	addProduct(&inventory, "Phone", 800, 10, "Electronics")
 	addProduct(&inventory, "Phone", 800, 10, Electronics)
 
 	// Display updated inventory

go/02-next-level/02-struct-embedding.go

@@ -1,40 +0,0 @@
-package main
-
-import "fmt"
-
-type Person struct {
-	Name string
-}
-
-func (p Person) Say() {
-	fmt.Println("Hi, my name is", p.Name)
-}
-
-type Student struct {
-	Person   //struct Person is embedded
-	Semester int
-}
-
-type Teacher struct {
-	Person  //struct Person is embedded
-	Subject string
-}
-
-func main() {
-
-	max := Person{"Max"}
-
-	daniel := Student{Person{"Daniel"}, 3}
-
-	sebastian := Teacher{Person{"Sebastian"}, "PR3"}
-
-	max.Say()
-
-	daniel.Say() //can be invoked directly on Student
-
-	sebastian.Say() //can be invoked directly on Teacher
-
-	max = sebastian.Person
-
-	max.Say()
-}

go/02-next-level/03-errors.go

@@ -1,62 +0,0 @@
-package main
-
-import (
-	"errors"
-	"fmt"
-)
-
-// a function that can fail, so it returns an error as the second return value
-func f(arg int) (int, error) {
-	if arg == 42 {
-		// in case of an error, return the zero value for the result and a non-nil error
-		return 0, errors.New("can't work with 42")
-	}
-
-	// simply return the result and a nil error in the success case
-	return arg + 3, nil
-}
-
-// define some errors to use in makeTea
-var ErrOutOfTea = fmt.Errorf("no more tea available")
-var ErrPower = fmt.Errorf("can't boil water")
-
-// a function that can fail in multiple ways, so it returns an error as the second return value
-func makeTea(arg int) error {
-	if arg == 2 {
-		// return the error directly, so we can check for it later with errors.Is
-		return ErrOutOfTea
-	} else if arg == 4 {
-		// use %w to wrap the error, so we can check for it later with errors.Is
-		return fmt.Errorf("making tea: %w", ErrPower)
-	}
-	return nil
-}
-
-func main() {
-	for _, i := range []int{7, 42} {
-
-		//typical pattern for checking errors in Go: if the error is not nil, handle it and return or continue; otherwise, use the result
-		if r, e := f(i); e != nil {
-			fmt.Println("f failed:", e)
-		} else {
-			fmt.Println("f worked:", r)
-		}
-	}
-
-	for i := range 5 {
-		if err := makeTea(i); err != nil {
-
-			// use errors.Is to check for specific errors, even if they are wrapped
-			if errors.Is(err, ErrOutOfTea) {
-				fmt.Println("We should buy new tea!")
-			} else if errors.Is(err, ErrPower) { // this error is wrapped, but errors.Is can still check for it
-				fmt.Println("Now it is dark.")
-			} else {
-				fmt.Printf("unknown error: %s\n", err)
-			}
-			continue
-		}
-
-		fmt.Println("Tea is ready!")
-	}
-}

go/02-next-level/04-closure.go

@@ -1,28 +0,0 @@
-package main
-
-import "fmt"
-
-// a closure is a function value that references variables from outside its body.
-// The function may access and assign to the referenced variables; in this sense the function is "bound" to the variables.
-func intSeq() func() int { //returns a function that returns an int
-	i := 0              // i is a variable that intSeq's function value will reference. It continues to exist even after intSeq returns.
-	return func() int { // the anonomous function is returned here. It is not executed yet.
-		i++
-		return i
-	}
-}
-
-func main() {
-
-	//functions are first class citizens in Go, so we can assign them to variables,
-	// pass them as arguments to other functions, and return them from functions.
-	nextInt := intSeq()
-
-	fmt.Println(nextInt())
-	fmt.Println(nextInt())
-	fmt.Println(nextInt())
-
-	//a second function value from intSeq, with its own i variable.
-	newInts := intSeq()
-	fmt.Println(newInts())
-}