Agrani Bank Ltd. Officer (ICT) Written Test: 2017প্রশ্ন ও সমাধান

.NET Framework is a software development platform by Microsoft for building and running Windows applications, providing a large class library and a managed runtime environment that handles memory management, security, and cross-language interoperability.

graph TD
    NET[".NET Framework"] --> CLR["CLR - Common Language Runtime"]
    NET --> FCL["FCL/BCL - Framework/Base Class Library"]
    NET --> CLS["CLS - Common Language Specification"]
    NET --> CTS["CTS - Common Type System"]
    NET --> ASP["ASP.NET - Web apps"]
    NET --> ADO["ADO.NET - Data access"]
    NET --> WinForms["Windows Forms / WPF - Desktop UI"]
    CLR --> JIT["JIT Compiler"]
    CLR --> GC["Garbage Collector"]

Main components:

• CLR (Common Language Runtime): the execution engine — manages memory (via GC), enforces type/code-access security, and JIT-compiles the intermediate language (IL/MSIL) into native machine code at runtime.
• FCL / BCL (Framework/Base Class Library): a huge collection of reusable, pre-built classes (collections, I/O, threading, networking, etc.) available to any .NET language.
• CTS (Common Type System): defines how types are declared, used, and managed, so different .NET languages share a compatible type system.
• CLS (Common Language Specification): a subset of rules that, if followed, guarantees cross-language interoperability (e.g., a C# library can be consumed from VB.NET).
• ASP.NET: framework for building web applications and services.
• ADO.NET: framework for database access and data manipulation.
• Windows Forms / WPF: frameworks for building desktop GUI applications.

Key benefit — language interoperability: code written in C#, VB.NET, or F# all compiles down to the same Intermediate Language (IL), runs on the same CLR, and can freely call into each other's libraries.

Exam takeaway: .NET Framework = CLR (execution + memory management) + BCL/FCL (class library) + CTS/CLS (type system and cross-language rules), plus higher-level frameworks like ASP.NET, ADO.NET, WinForms/WPF built on top.

	localStorage	sessionStorage
Lifetime	Persists indefinitely, until explicitly cleared (by code or the user)	Cleared automatically when the tab/window is closed
Scope	Shared across all tabs/windows of the same origin	Isolated to a single tab/window — even the same page opened in two tabs gets separate storage
Typical use	Remembering user preferences, theme, "remember me" tokens	Multi-step form data, one-time session flags, per-tab wizard state
Capacity	~5-10 MB (browser-dependent)	Same as localStorage, but scoped per tab
API	localStorage.setItem(key, value) / getItem(key) / removeItem(key)	sessionStorage.setItem(...) — identical API, different object

// localStorage - survives even after the browser is closed and reopened
localStorage.setItem("theme", "dark");
console.log(localStorage.getItem("theme"));   // "dark" (still there tomorrow)

// sessionStorage - gone once this tab is closed
sessionStorage.setItem("draftText", "Hello world");
console.log(sessionStorage.getItem("draftText"));

• Both store data only as strings (use JSON.stringify()/JSON.parse() for objects) and both are accessible only via JavaScript on the client — unlike cookies, neither is sent automatically with every HTTP request.

Exam takeaway: localStorage = persistent, cross-tab, until manually cleared; sessionStorage = temporary, single-tab, cleared when that tab closes.