From 60bc9586d16c1d259fd34e4376891d9a70d95697 Mon Sep 17 00:00:00 2001
From: Sebastian Steger <s.steger@hs-mannheim.de>
Date: Wed, 20 Aug 2025 06:27:04 +0000
Subject: [PATCH] go basics

---
 go/01-basics/README.md     | 84 ++++++++++++++++++++++++++++++++++++++
 go/01-basics/calculator.go | 22 ++++++++++
 go/01-basics/inventory.go  | 50 +++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 go/01-basics/README.md
 create mode 100644 go/01-basics/calculator.go
 create mode 100644 go/01-basics/inventory.go

diff --git a/go/01-basics/README.md b/go/01-basics/README.md
new file mode 100644
index 0000000..8ef91a5
--- /dev/null
+++ b/go/01-basics/README.md
@@ -0,0 +1,84 @@
+# Go By Example
+<https://gobyexample.com/>
+
+
+# Assignment 1 - Simple Calculator
+
+## Objective
+Write a Go program that performs basic mathematical operations (addition, subtraction, multiplication, and division) based on user input.
+
+## Steps
+
+1. Define constants for valid operations (*add*,*subtract*,*multiply*,*divide*).
+2. Use variables to store user inputs and computed results.
+3. Use a  loop to allow the user to perform multiple calculations until they choose to exit.
+4. Validate inputs using  statements (e.g., handle division by zero).
+5. Use a  statement to perform the selected mathematical operation.
+
+## Example Output
+```
+Enter operation (add, subtract, multiply, divide, exit): add
+Enter the first number: 5
+Enter the second number: 3
+Result: 8
+
+Enter operation (add, subtract, multiply, divide, exit): divide
+Enter the first number: 10
+Enter the second number: 0
+Error: Division by zero is not allowed!
+
+Enter operation (add, subtract, multiply, divide, exit): exit
+Goodbye!
+```
+
+## Hint
+The program can use the `fmt.Scan` function to accept user input.
+
+# Assignment 2 - Inventory Management System
+
+## Objective
+Create a program that simulates an inventory management system for a store.
+
+## Steps
+1. Define product categories (e.g., Electronics, Groceries, Clothes) using `const` and `iota`.
+2. Store a fixed list of initial product names in an **array**.
+3. Convert the array into a **slice** so the inventory can grow or shrink dynamically.
+4. Use a **map** to associate product names with details like quantity, price, and category.
+5. Implement the following **functions**:
+    - *AddProduct*: Add a new product to the inventory.
+    - *RemoveProduct*: Remove a product from the inventory.
+    - *DisplayInventory*: Display all products with their details.
+    - *UpdateQuantity*: Update the quantity of a product.
+
+## Example Output
+```
+Welcome to the Inventory Manager!
+
+Initial Inventory:
+1. Laptop - Electronics (Price: $1000, Quantity: 5)
+2. Apples - Groceries (Price: $2, Quantity: 50)
+3. T-shirt - Clothes (Price: $10, Quantity: 20)
+
+Adding a new product: Phone (Electronics, Price: $800, Quantity: 10)
+
+Updated Inventory:
+1. Laptop - Electronics (Price: $1000, Quantity: 5)
+2. Apples - Groceries (Price: $2, Quantity: 50)
+3. T-shirt - Clothes (Price: $10, Quantity: 20)
+4. Phone - Electronics (Price: $800, Quantity: 10)
+
+Updating quantity for Apples: New Quantity = 30
+
+Removing product: T-shirt
+
+Final Inventory:
+1. Laptop - Electronics (Price: $1000, Quantity: 5)
+2. Apples - Groceries (Price: $2, Quantity: 30)
+3. Phone - Electronics (Price: $800, Quantity: 10)
+```
+
+- Use **arrays** to store initial product information.
+- Use **slices** to dynamically manage items in the inventory.
+- Use **maps** to track product details (e.g., quantity or price).
+- Define **functions** for adding, removing, and displaying products.
+- Use **enums** (via constants) to represent product categories.
diff --git a/go/01-basics/calculator.go b/go/01-basics/calculator.go
new file mode 100644
index 0000000..7686df8
--- /dev/null
+++ b/go/01-basics/calculator.go
@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+
+	//TODO: implement according to README.md
+
+	//the following code just demonstrates how to use fmt.Scan
+
+	var str string
+	fmt.Print("Please enter a string: ")
+	fmt.Scan(&str)
+
+	var x float64
+	fmt.Print("Please enter a float: ")
+	fmt.Scan(&x)
+
+	fmt.Printf("You entered '%s' and %f\n", str, x)
+}
diff --git a/go/01-basics/inventory.go b/go/01-basics/inventory.go
new file mode 100644
index 0000000..209c374
--- /dev/null
+++ b/go/01-basics/inventory.go
@@ -0,0 +1,50 @@
+package main
+
+type Product struct {
+	Name     string
+	Price    float64
+	Quantity int
+	Category string //TODO: use enum instead
+}
+
+func addProduct(inventory *[]Product, name string, price float64, quantity int, category string) {
+	//TODO: implement
+}
+
+func removeProduct(inventory *[]Product, name string) {
+	//TODO: implement
+}
+
+func updateQuantity(inventory *[]Product, name string, newQuantity int) {
+	//TODO: implement
+}
+
+func displayInventory(inventory []Product) {
+	//TODO: implement
+}
+
+func main() {
+	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"},
+	}
+
+	// Display initial inventory
+	displayInventory(inventory)
+
+	// Add a new product
+	addProduct(&inventory, "Phone", 800, 10, "Electronics")
+
+	// Display updated inventory
+	displayInventory(inventory)
+
+	// Update the quantity of an existing product
+	updateQuantity(&inventory, "Apples", 30)
+
+	// Remove a product
+	removeProduct(&inventory, "T-shirt")
+
+	// Display final inventory
+	displayInventory(inventory)
+}