🖼️ UML Diagrams with Examples

🔹 What is UML?

UML (Unified Modeling Language) ek standardized modeling language hai jo software systems ko visualize, specify, construct, aur document karne ke liye use hota hai.

• UML diagrams developers ko system samajhne, design karne aur maintain karne me madad karte hain.

• Ye mainly OOAD (Object-Oriented Analysis & Design) me use hote hain.

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🔹 Types of UML Diagrams

UML diagrams 2 categories me divide hote hain:

1. Structural Diagrams – system ki static structure show karte hain.

   • Class Diagram

   • Object Diagram

   • Component Diagram

   • Deployment Diagram

2. Behavioral Diagrams – system ke dynamic behavior show karte hain.

   • Use Case Diagram

   • Sequence Diagram

   • Activity Diagram

   • State Diagram

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🔹 Examples of UML Diagrams (Online Shopping System)

1. Class Diagram

• System ke classes, attributes, methods aur relationships show karta hai.
  📌 Example:

• Classes: Customer, Product, Cart, Order, Payment

• Relationships: Customer → places Order → Order uses Payment

👉 (Diagram already bana diya tha, tu use kar sakta hai)

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2. Use Case Diagram

• User aur system ke interactions show karta hai.
  📌 Example:

• Actor: Customer

• Use Cases: Browse Product, Add to Cart, Place Order, Make Payment

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3. Sequence Diagram

• Objects ke beech ke messages ka order show karta hai.
  📌 Example:

• Customer → Cart → Order → Payment

• Flow: Customer selects Product → Cart updates → Order created → Payment processed

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4. Activity Diagram

• Process ka workflow show karta hai.
  📌 Example:

• Customer Login → Browse Products → Add to Cart → Checkout → Payment Success/Fail

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🔹 Why UML is Important?

• ✅ Clear system visualization

• ✅ Easy communication among developers & stakeholders

• ✅ Helps in documentation and future maintenance

• ✅ Reduces complexity by breaking system into parts