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A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

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a language used to control the presentation of HTML and XML documents including colors, layout, and fonts.
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When the code scales so poorly in the face of large inputs that it cannot complete in a reasonable amount of time, use this instead of the [performance] tag.
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for questions that came up in an interview.
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a paradigm which attempts to solve computational problems by the chained evaluation of functions whose output is determined by their inputs rather than the program state. In…
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an event based, asynchronous I/O framework that uses Google's V8 JavaScript engine. Node.js is commonly used for heavy client-server JavaScript applications.
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a graph in which there is exactly one path between any two nodes. It is often used as a hierarchical data structure.
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Google's software stack for mobile devices. For non-developer questions, see
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used for questions which present a problem and multiple solutions, where the asker wishes to know which solution is best (and why).
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a declarative language, mainly used for pattern matching within strings. Please include a tag specifying the programming language you are using, together with this tag.
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JSON (JavaScript Object Notation) aka the Fat Free Alternative to XML is a lightweight data exchange format inspired by JavaScript object literals. It is often used with JavaScript, Ajax, and RESTful …
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A block of arbitrary information, or resource for storing information, accessible by the string-based name or path. Files are available to computer programs and are usually based on some kind of persi…
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for questions pertaining to random numbers, whether pseudo random or truly random.
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security applied to computing devices such as computers and smartphones, as well as to both private and public computer networks, including the whole Internet.
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reinventing the wheel, but are doing it anyways. Questions with this tag involve code that is already fully implemented (such as from a library).
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used to check data to make sure it fits whatever required specifications are set for it.
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numbers which are divisible only by themselves and one, starting with 2, 3, 5, 7, 11.... They are commonly used in encryption and hashing algorithms.
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for questions related to the loading, formatting, saving, compression, and display of data representing pictures.
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the GNU Bourne Again SHell, the successor to the classic Unix Bourne sh (shell). It's the default shell for various GNU systems.
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an open-source web development framework written in Ruby. If your question code is written in Ruby on Rails, tag with Ruby as the language tag. Many things are defined by convention, …
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an abstract representation of objects (vertices) connected by links (edges). For questions about plotting data graphically, use the [data-visualization] tag instead.
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A mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks.
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a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages.
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The various techniques used for maintaining stable program state in circumstances that, if not taken care of ("handled"), could cause serious issues, including logical bugs and abrupt execution termin…
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A comma-separated values (CSV) file stores tabular data (numbers and text) as plain text, with rows and columns delimited by line terminators and commas, respectively. You may also use this tag for va…
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for reviews of code that performs file system operations, such as creating, deleting, renaming, moving, copying, reading, and writing files.
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a relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases. It originated from the Sybase SQL Server codebase,…
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In mathematics, a matrix (plural matrices) is a rectangular array of numbers, symbols, or expressions, arranged in rows and columns. The individual items in a matrix are called its elements or entries…
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a multi-paradigm, compiled programming language developed by Apple for iOS and OS X development.
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a design pattern for computer user interfaces that divides an application into three areas of responsibility. It is often applied to websites.
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the act of managing computer memory by allocating portions of memory to programs as well as freeing memory so that it can be re-used.
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the fundamental package for scientific computing with the programming language Python.
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a general purpose programming language principally targeting the Java Virtual Machine. Designed to express common programming patterns in a concise, elegant, and type-safe way, it fuses both …
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A generic term meaning the process by which text transformed into a more meaningful or clearer output. A typical example would be the transformation of a decimal into a particular currency format with…
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Questions requesting help with school homework. This tag lets potential answerers know that they should GUIDE the student in solving the problem, rather than showing a complete solution. CAUTION: Befo…
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the use of a program to simulate human interaction with a web server or to extract specific information from a web page.
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for questions about calculators.