Core Web Development Concepts: Node.js, MongoDB, APIs, React
Web Application Fundamentals
Understanding Middleware
Middleware is a function that acts as a bridge between the incoming request from the client and the outgoing response from the server in a web application. It plays a crucial role in processing requests before they reach the final route handler and handling responses before they are sent back to the client. Middleware functions operate sequentially, with each middleware having access to the request and response objects, as well as a next function.
Dingoo Controls: Mame4All, Stella, Gmu, Snes9x, PicoDrive, DOOEngine, Audio & Video Player
Dingoo Control Reference
Mame4All
- Insert coin: Select + Start
- Start game: A
- Exit: Select + L + R
- Pause: Select + X
- Mame menu: Select + A
- Volume etc.: Select + B
- Show fps/profiler: Select + L/R
Stella
- A: Fire!/Select
- B: Cancel
- L: Options menu
- Start: Commands menu
- Select: Quit
In menus, L jumps from control to control, A selects, and B cancels.
Gmu Audio Player
- A: Restart track
- B: Play mode (continuous, repeat, etc.)
- X: Play/pause
- Y: Remove track
- Start: Toggle cover art, track info, file browse, etc.
- Select: No function
- Shoulder
Operating System Fundamentals: Core Concepts & Algorithms
Operating System Introduction & Types
Operating systems manage CPU, memory, storage, and I/O resources.
Types of Operating Systems
- OS-less
- Batch Processing
- Multiprogramming
- Time-sharing
Multiprogramming
Increases CPU utilization; memory and security management are crucial.
Time-sharing
Enables user interaction and provides quicker system response.
Computing Resources & OS Services
Key Operating System Services
- User Interface (CLI/GUI)
- Program Execution
- I/O Operations
- File System Manipulation
- Inter-process
Android Security: Kotlin Coding Practices & Intent Handling
🔧 Kotlin & Android Coding Terms You Must Know
?.let {}: Kotlin null-safe scope function. Prevents crashes if an object is null; not a security check.getCallingPackage(): Identifies the app that sent an intent. Use this to verify the intent source.checkCallingOrSelfPermission(): Checks if a permission is declared. Does not verify the actual identity of the sender.resolveActivity(intent, 0): Checks if the intent can be handled. Prevents app crashes, but not a security check.putExtra()/getStringExtra(
Database Systems & Data Warehousing Concepts
Data Warehouse Architectures
Metadata in Knowledge Data Lifecycle
Examples of metadata that can be used at every step of the Knowledge Data Lifecycle:
- Data Selection: Data description, date of data, structures, data sources, extraction mechanisms.
- Data Pre-processing: Cleaning logs, methods, missing values.
- Data Mining & Machine Learning: Data types for algorithms, size of dataset.
- Evaluation & Interpretation: Knowledge derived, data mining patterns.
CSV vs. DBMS: Advantages Comparison
Advantages
Read MoreComputer I/O Interfaces and Data Transfer Techniques
Understanding Computer I/O Interfaces
The input/output (I/O) interface provides a method for transferring information between internal storage devices and external I/O peripherals. Peripherals connected to a computer require a special communication link to operate as an interface with the Central Processing Unit (CPU). The purpose of this communication link is to resolve the differences and focus the computer’s attention on each peripheral. The main differences are:
- Electromechanical vs. Electronic