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Less-than Sign
The less-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the left, , has been found in documents dated as far back as the 1560s. In mathematical writing, the less-than sign is typically placed between two values being compared and signifies that the first number is less than the second number. Examples of typical usage include and . Since the development of computer programming languages, the less-than sign and the greater-than sign have been repurposed for a range of uses and operations. Computing The less-than sign, , is an original ASCII character (hex 3C, decimal 60). Programming In BASIC, Lisp-family languages, and C-family languages (including Java and C++), comparison operator < means "less than". In Coldfusion, operator .lt. means "less than". In Fortran, operator .LT. means "less than"; later versions allow <. Shell scripts In Bourne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode
Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 Character (computing), characters and 168 script (Unicode), scripts used in various ordinary, literary, academic, and technical contexts. Unicode has largely supplanted the previous environment of a myriad of incompatible character sets used within different locales and on different computer architectures. The entire repertoire of these sets, plus many additional characters, were merged into the single Unicode set. Unicode is used to encode the vast majority of text on the Internet, including most web pages, and relevant Unicode support has become a common consideration in contemporary software development. Unicode is ultimately capable of encoding more than 1.1 million characters. The Unicode character repertoire is synchronized with Univers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruby (programming Language)
Ruby is a general-purpose programming language. It was designed with an emphasis on programming productivity and simplicity. In Ruby, everything is an object (computer science), object, including primitive data types. It was developed in the mid-1990s by Yukihiro Matsumoto, Yukihiro "Matz" Matsumoto in Japan. Ruby is interpreted language, interpreted, high-level programming language, high-level, and Dynamic typing, dynamically typed; its interpreter uses garbage collection (computer science), garbage collection and just-in-time compilation. It supports multiple programming paradigms, including procedural programming, procedural, object-oriented programming, object-oriented, and functional programming. According to the creator, Ruby was influenced by Perl, Smalltalk, Eiffel (programming language), Eiffel, Ada (programming language), Ada, BASIC, and Lisp (programming language), Lisp. History Early concept According to Matsumoto, Ruby was conceived in 1993. In a 1999 post to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bracket
A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. They come in four main pairs of shapes, as given in the box to the right, which also gives their names, that vary between British and American English. "Brackets", without further qualification, are in British English the ... marks and in American English the ... marks. Other symbols are repurposed as brackets in specialist contexts, such as those used by linguists. Brackets are typically deployed in symmetric pairs, and an individual bracket may be identified as a "left" or "right" bracket or, alternatively, an "opening bracket" or "closing bracket", respectively, depending on the directionality of the context. In casual writing and in technical fields such as computing or linguistic analysis of grammar, brackets nest, with segments of bracketed material containing embedded within them other further bracketed sub-segments. The nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Generalized Markup Language
The Standard Generalized Markup Language (SGML; ISO 8879:1986) is a standard for defining generalized markup languages for documents. ISO 8879 Annex A.1 states that generalized markup is "based on two postulates": * Declarative: Markup should describe a document's structure and other attributes rather than specify the processing that needs to be performed, because it is less likely to conflict with future developments. * Rigorous: In order to allow markup to take advantage of the techniques available for processing, markup should rigorously define objects like programs and databases. DocBook SGML and LinuxDoc are examples which used SGML tools. Standard versions SGML is an ISO standard: "ISO 8879:1986 Information processing – Text and office systems – Standard Generalized Markup Language (SGML)", of which there are three versions: * Original ''SGML'', which was accepted in October 1986, followed by a minor Technical Corrigendum. * ''SGML (ENR)'', in 1996, resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTML
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript, a programming language. Web browsers receive HTML documents from a web server or from local storage and browser engine, render the documents into multimedia web pages. HTML describes the structure of a web page Semantic Web, semantically and originally included cues for its appearance. HTML elements are the building blocks of HTML pages. With HTML constructs, HTML element#Images and objects, images and other objects such as Fieldset, interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, Hyperlink, links, quotes, and other items. HTML elements are delineated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spaceship Operator
In computer science, a three-way comparison takes two values A and B belonging to a type with a total order and determines whether A < B, A = B, or A > B in a single operation, in accordance with the mathematical law of trichotomy. It can be implemented in terms of a function (such as strcmp in C), a method (such as compareTo in Java), or an operator (such as the spaceship operator in Perl, PHP and C++). Machine-level computation Many processors have instruction sets that support such an operation on primitive types. Some machines have signed integers based on a sign-and-magnitude or ones' complement representation (see signed number representations), both of which allow a differentiated positive and negative zero. This does not violate trichotomy as long as a consistent total order is adopted: either −0 = +0 or −0 < +0 is valid. Common floating point types, however, have an exception to trichotomy: there is a special value "NaN" ( Not a Number) such that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyphen-minus
The symbol , known in Unicode as hyphen-minus, is the form of hyphen most commonly used in digital documents. On most keyboards, it is the only character that resembles a minus sign or a dash, so it is also used for these. The name ''hyphen-minus'' derives from the original ASCII standard, where it was called ''hyphen (minus)''. The character is referred to as a ''hyphen'', a ''minus sign'', or a ''dash'' according to the context where it is being used. Description In early typewriters and character encodings, a single key/code was almost always used for hyphen, minus, various dashes, and strikethrough, since they all have a similar appearance. The current Unicode Standard specifies distinct characters for several different dashes, an unambiguous minus sign (sometimes called the ''Unicode minus'') at code point U+2212, an unambiguous hyphen (sometimes called the ''Unicode hyphen'') at U+2010, the hyphen-minus at U+002D and a variety of other hyphen symbols for various uses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R (programming Language)
R is a programming language for statistical computing and Data and information visualization, data visualization. It has been widely adopted in the fields of data mining, bioinformatics, data analysis, and data science. The core R language is extended by a large number of R package, software packages, which contain Reusability, reusable code, documentation, and sample data. Some of the most popular R packages are in the tidyverse collection, which enhances functionality for visualizing, transforming, and modelling data, as well as improves the ease of programming (according to the authors and users). R is free and open-source software distributed under the GNU General Public License. The language is implemented primarily in C (programming language), C, Fortran, and Self-hosting (compilers), R itself. Preprocessor, Precompiled executables are available for the major operating systems (including Linux, MacOS, and Microsoft Windows). Its core is an interpreted language with a na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows PowerShell
PowerShell is a shell program developed by Microsoft for task automation and configuration management. As is typical for a shell, it provides a command-line interpreter for interactive use and a script interpreter for automation via a language defined for it. Originally only for Windows, known as Windows PowerShell, it was made open-source and cross-platform on August 18, 2016, with the introduction of PowerShell Core. The former is built on the .NET Framework; the latter on .NET (previously .NET Core). PowerShell is bundled with current versions of Windows and can be installed on macOS and Linux. Since Windows 10 build 14971, PowerShell replaced Command Prompt as the default command shell exposed by File Explorer. In PowerShell, administrative tasks are generally performed via ''cmdlets'' (pronounced ''command-lets''), which are specialized .NET classes implementing a particular operation. These work by accessing data in different data stores, like the file system or W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolog
Prolog is a logic programming language that has its origins in artificial intelligence, automated theorem proving, and computational linguistics. Prolog has its roots in first-order logic, a formal logic. Unlike many other programming languages, Prolog is intended primarily as a declarative programming language: the program is a set of facts and Horn clause, rules, which define Finitary relation, relations. A computation is initiated by running a ''query'' over the program. Prolog was one of the first logic programming languages and remains the most popular such language today, with several free and commercial implementations available. The language has been used for automated theorem proving, theorem proving, expert systems, term rewriting, type systems, and automated planning, as well as its original intended field of use, natural language processing. See also Watson (computer). Prolog is a Turing-complete, general-purpose programming language, which is well-suited for inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinclair BASIC
Sinclair BASIC is a dialect of the programming language BASIC used in the 8-bit home computers from Sinclair Research, Timex Sinclair and Amstrad. The Sinclair BASIC interpreter was written by Nine Tiles Networks Ltd. Designed to run in only 1 KB of RAM, the system makes a number of decisions to lower memory usage. This led to one of Sinclair BASIC's most notable features, that the keywords were entered using single keystrokes; each of the possible keywords was mapped to a key on the keyboard, when pressed, the token would be placed into memory while the entire keyword was printed out on-screen. This made code entry easier whilst simplifying the parser. The original ZX80 version supported only integer mathematics, which partially made up for some of the memory-saving design notes which had negative impact on performance. When the system was ported to the ZX81 in 1981, a full floating point implementation was added. This version was very slow, among the slowest BASICs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPath
XPath (XML Path Language) is an expression language designed to support the query or transformation of XML documents. It was defined by the World Wide Web Consortium (W3C) in 1999, and can be used to compute values (e.g., strings, numbers, or Boolean values) from the content of an XML document. Support for XPath exists in applications that support XML, such as web browsers, and many programming languages. The XPath language is based on a tree representation of the XML document, and provides the ability to navigate around the tree, selecting nodes by a variety of criteria. In popular use (though not in the official specification), an XPath expression is often referred to simply as "an XPath". Originally motivated by a desire to provide a common syntax and behavior model between XPointer and XSLT, subsets of the XPath query language are used in other W3C specifications such as XML Schema, XForms and the Internationalization Tag Set (ITS). XPath has been adopted by a num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
