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39.1 Backpack Weight Calculator 1, practice (JS lessons)

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📘 Task: Backpack Weight Calculator

Create an application "Backpack Weight Calculator".

Imagine you are going on a hike. Before you leave, you need to pack your backpack.

The user must choose one item from each category. After clicking the button, calculate the total weight of the backpack.

🥤 Category 1 — Drink

• 💧 Water — 2 kg
• 🧃 Juice — 3 kg
• 🥤 Soda — 4 kg
• 🍵 Tea Thermos — 5 kg
• 🚰 Water Canister — 8 kg

🍎 Category 2 — Food

• 🍎 Apples — 2 kg
• 🥪 Sandwiches — 3 kg
• 🥫 Canned Food — 5 kg
• 🍱 Food Pack — 7 kg
• 📦 Food Box — 10 kg

🛠️ Category 3 — Tool

• 🔦 Flashlight — 1 kg
• 🔪 Knife — 2 kg
• 🪏 Shovel — 5 kg
• 🪓 Axe — 7 kg
• 🧰 Tool Kit — 10 kg

🧥 Category 4 — Clothing

• 👕 T-Shirt — 1 kg
• 🧥 Sweater — 3 kg
• 🧥 Jacket — 5 kg
• 🥾 Warm Clothes — 7 kg
• ❄️ Winter Clothes — 10 kg

📐 Rules:

• Determine the weight of each selected item.
• Add up the weight of all four selected items.
• If the total weight is less than 10 kg — display the message:
  Too light!
• If the total weight is greater than 31 kg — display the message:
  Too heavy!
• If the weight is within the range of 7 to 31 kg — display:
  "Backpack weight: 24 kg"

📐 How it works:

• Get the values of all four <select> elements.
• Use switch to determine the weight of each selected item.
• Add all the values into a single variable.
• Check the total weight using if.
• Display the final message.

🧪 Example:

The user selected:

• 🍵 Tea Thermos — 5 kg
• 🥫 Canned Food — 5 kg
• 🪓 Axe — 7 kg
• 🧥 Jacket — 5 kg

Backpack weight: 25 kg