Variables

Batch Script Quick Reference

A condensed lookup of essential Windows batch syntax — variables, control flow, string operations, and exit codes — for day-to-day scripting.

Batch Script Syntax Basics

The core syntax rules of batch scripting: variables, delayed expansion, conditionals, and loops.

Environment Variables in Batch

Understand how Windows Batch scripts create, read, scope, and persist environment variables, including the tricky topic of delayed expansion.

Variables in Batch Scripts

Learn how Windows batch scripts store, read, and manipulate values using the set command, environment variables, delayed expansion, and substring syntax.

Variables: Set and UpdateContext

Power Apps has two kinds of variables — global, created with Set, and screen-scoped context variables, created with UpdateContext — each suited to different si…

Collection and Global Variables

Learn the difference between collection variables, scoped to one collection, and global variables, available everywhere, and when to use each.

Dynamic Variables and Faker Data

How to use Postman's built-in dynamic variables like {{$guid}} and {{$randomEmail}} to generate realistic fake data on every request.

Environments and Variables

Understand how Postman Environments let you swap base URLs, tokens, and config values between dev, staging, and production without editing every request.

Postman Quick Reference

A condensed cheat sheet of Postman variable scopes, common pm.* scripting snippets, and Newman CLI commands for everyday use.

Environment Variables and Configuration

Learn how Cypress resolves environment variables across config files, OS variables, and the CLI, and how fixtures supply deterministic test data.

Variables and Templating

Learn how Airflow Variables provide runtime configuration and how Jinja templating lets task parameters be computed dynamically at execution time.

Variables and Data Types

How PowerShell stores data in loosely-typed variables, the common .NET types you'll use daily, and how to cast and inspect types explicitly.

DAX Variables and Iterators

VAR and RETURN make complex DAX measures more readable and performant by caching intermediate results, especially when combined with iterator functions.

Variables in Flows

How to declare, set, and accumulate values in flow-scoped variables, and where they go wrong inside loops.

Temp Tables and Table Variables

Compare local temp tables, global temp tables, and table variables in SQL Server, and learn when each is the right tool for intermediate result sets.

Variables and Control Flow

Learn how T-SQL variables store scalar values inside a batch and how IF/ELSE and WHILE let you branch and loop through procedural logic.

Fortran Data Types and Variables

An overview of Fortran's intrinsic data types, integer, real, character, logical, and complex, and how to declare and initialize variables.

Pascal Data Types and Variables

An overview of Pascal's built-in data types, variable declarations, and how the language's strict typing shapes everyday code.

Apex Syntax and Variables

Covers the foundational rules of Apex syntax, how to declare and scope variables, naming conventions, and how comments structure readable code.

Trigger Context Variables

A guide to Trigger.new, Trigger.old, their map equivalents, and the boolean context flags that let a single handler branch correctly across all seven trigger c…

Built-in Variables in AWK

AWK ships with a set of predefined variables such as NR, NF, FS, and OFS that expose the current record, field counts, and formatting controls without any setu…

User-Defined Variables in AWK

Beyond built-ins, AWK lets you create your own scalar and associative-array variables with dynamic typing and automatic initialization, powering counters, accu…

Arduino Data Types and Variables

Learn the core Arduino/C++ data types, how much memory each uses on an 8-bit AVR, and how to declare variables and constants correctly to avoid overflow and wa…

Solidity Syntax and Variables

Understand Solidity's file structure, the difference between state, local, and global variables, and how visibility and data location affect where values live…

Python Cheat Sheet

A quick reference for Python syntax, data structures, and common functions.

JavaScript Cheat Sheet

Essential JavaScript concepts, ES6+ features, and common methods.

Dark Mode Implementation Cheat Sheet

Covers CSS custom-property theming, prefers-color-scheme, flash-of-wrong-theme prevention, persisted toggle logic, and Tailwind's class-based dark mode setup.