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Your guide: Miss HiraExplains computers with chai, cricket and your phone.
A builder needs a drawing before building a house. So does a programmer.
This lesson covers drawings, patterns, tests and tools.
Four diagrams first.
UML is a standard way to draw the design of a software system. Pictures make complex systems easy to understand, share and manage.
Use case diagram: shows what the system does from the user's side. An actor is a person or another system. A use case is a complete goal.
Four steps to find use cases: identify actors, define goals, outline interactions, validate with stakeholders.
Class diagram: a map of how things are organised. A class is like a box. Attributes are what it holds. Methods are what it can do. In the book's room example, Box is the general class and ToyBox, BookBox and ClothesBox are special boxes.
Sequence diagram: shows how objects send messages to each other in order, over time. In the book, the user sends open(), then puts items inside, then sends close() to each box.
Activity diagram: the flow of steps in a process, with decisions. Book example: Order Placement, Food Preparation, then a decision Food Ready? No goes back to Re-Prepare Food. Yes goes to Order Delivery.
Design patterns are common solutions to common problems. They act like templates. They make coding easier, faster and more consistent.
Singleton: make sure one object exists only once and reuse it. Factory: a workshop. You say what you need and it builds it. Observer: one source tells all watchers when something changes. Strategy: a toolbox. Pick the right tool for the task.
Benefits: less code complexity, more reuse, a shared vocabulary for developers.
Debugging is finding and fixing bugs. Tools: debuggers (step through code), print statements (show variable values), code reviews.
Testing moves from small to big: unit testing (one function alone), integration testing (modules together), system testing (whole system), acceptance testing (ready for release, done by end-users).
Language editors: Notepad++ and VS Code. Translators: interpreters translate line by line (Python); compilers translate all at once (GCC). Debuggers: GDB and the Visual Studio Debugger.
An IDE puts the editor, compiler, debugger and version control in one place. Examples: Visual Studio, PyCharm.
Online platforms run in the cloud (Repl.it, Gitpod). Offline platforms run on your own computer. Source code repositories store code and track changes: GitHub, Bitbucket.
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A builder needs a drawing before building a house. So does a programmer.
This lesson covers drawings, patterns, tests and tools.
Four diagrams first.
UML is a standard way to draw the design of a software system. Pictures make complex systems easy to understand, share and manage.
Use case diagram: shows what the system does from the user's side. An actor is a person or another system. A use case is a complete goal.
Four steps to find use cases: identify actors, define goals, outline interactions, validate with stakeholders.
Class diagram: a map of how things are organised. A class is like a box. Attributes are what it holds. Methods are what it can do. In the book's room example, Box is the general class and ToyBox, BookBox and ClothesBox are special boxes.
Sequence diagram: shows how objects send messages to each other in order, over time. In the book, the user sends open(), then puts items inside, then sends close() to each box.
Activity diagram: the flow of steps in a process, with decisions. Book example: Order Placement, Food Preparation, then a decision Food Ready? No goes back to Re-Prepare Food. Yes goes to Order Delivery.
Design patterns are common solutions to common problems. They act like templates. They make coding easier, faster and more consistent.
Singleton: make sure one object exists only once and reuse it. Factory: a workshop. You say what you need and it builds it. Observer: one source tells all watchers when something changes. Strategy: a toolbox. Pick the right tool for the task.
Benefits: less code complexity, more reuse, a shared vocabulary for developers.
Debugging is finding and fixing bugs. Tools: debuggers (step through code), print statements (show variable values), code reviews.
Testing moves from small to big: unit testing (one function alone), integration testing (modules together), system testing (whole system), acceptance testing (ready for release, done by end-users).
Language editors: Notepad++ and VS Code. Translators: interpreters translate line by line (Python); compilers translate all at once (GCC). Debuggers: GDB and the Visual Studio Debugger.
An IDE puts the editor, compiler, debugger and version control in one place. Examples: Visual Studio, PyCharm.
Online platforms run in the cloud (Repl.it, Gitpod). Offline platforms run on your own computer. Source code repositories store code and track changes: GitHub, Bitbucket.
Q1. Book short question 5: purpose of a use case diagram.
It captures functional requirements, shows how users will interact with the system, and helps organise the work and design test cases.
Q2. Book class activity: actors and use cases for an online shop.
Actors: Customer, Administrator, Delivery Personnel. Use cases: Browse Products, Add Items to Cart, Make Purchase, Manage Product Listings, Process Orders, Handle Customer Inquiries, Update Delivery Status.
✗ “Unit testing checks the whole system.”
✓ Unit testing checks one small part alone. System testing checks the whole.
1. The purpose of use case diagrams is to:
(a) Book MCQ 7.
2. Which tool translates code line by line?
(a) A compiler translates all at once.
3. Which test is done by end-users to see if software is ready for release?
(a) Also called user acceptance testing.
4. A sequence diagram shows:
(a) Over time, in order.
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