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Flip-flop Operator
In computer programming, a flip-flop is a seldom-used syntactic construct which allows a boolean to flip from false to true when a first condition is met and then back to false when a second condition is met. The syntax is available in the programming languages Perl and Ruby. Similar logic is available in sed and awk. A flip-flop with first condition A and second condition B is not equivalent to "if A and not B", as the former has persistent state and is true even if A is no longer true, as long as at some point in the past A was true and B has always been false. Example The following Ruby code prints the numbers 4 through 6: (1..10).each do , x, puts x if (x 4 .. x 6) end The first instance of ".." is the range operator, which produces the enumeration An enumeration is a complete, ordered listing of all the items in a collection. The term is commonly used in mathematics and computer science to refer to a listing of all of the elements of a set. The precise requir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as analysis, generating algorithms, Profiling (computer programming), profiling algorithms' accuracy and resource consumption, and the implementation of algorithms (usually in a chosen programming language, commonly referred to as coding). The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. The purpose of programming is to find a sequence of instructions that will automate the performance of a task (which can be as complex as an operating system) on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the Domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl
Perl is a family of two High-level programming language, high-level, General-purpose programming language, general-purpose, Interpreter (computing), interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was officially changed to Raku (programming language), Raku in October 2019. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Data extraction, Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Raku, which began as a redesign of Perl 5 in 2000, eventually evolved into a separate language. Both languages continue to be developed independently by different development teams and liberally borrow ideas from each other. The Perl languages borrow featur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruby (programming Language)
Ruby is an interpreted, high-level, general-purpose programming language which supports multiple programming paradigms. It was designed with an emphasis on programming productivity and simplicity. In Ruby, everything is an object, including primitive data types. It was developed in the mid-1990s by Yukihiro "Matz" Matsumoto in Japan. Ruby is dynamically typed and uses garbage collection and just-in-time compilation. It supports multiple programming paradigms, including procedural, object-oriented, and functional programming. According to the creator, Ruby was influenced by Perl, Smalltalk, Eiffel, Ada, BASIC, Java and Lisp. History Early concept Matsumoto has said that Ruby was conceived in 1993. In a 1999 post to the ''ruby-talk'' mailing list, he describes some of his early ideas about the language: Matsumoto describes the design of Ruby as being like a simple Lisp language at its core, with an object system like that of Smalltalk, blocks inspired by highe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Range Operator
Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to identify a survey township in the US * Rangeland, deserts, grasslands, shrublands, wetlands, and woodlands that are grazed by domestic livestock or wild animals Mathematics * Range of a function, a set containing the output values produced by a function * Range (statistics), the difference between the highest and the lowest values in a set * Interval (mathematics), also called ''range'', a set of real numbers that includes all numbers between any two numbers in the set * Column space, also called the ''range'' of a matrix, is the set of all possible linear combinations of the column vectors of the matrix * Projective range, a line or a conic in projective geometry * Range of a quantifier, in logic Music * Range (music), the distance f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enumeration
An enumeration is a complete, ordered listing of all the items in a collection. The term is commonly used in mathematics and computer science to refer to a listing of all of the elements of a set. The precise requirements for an enumeration (for example, whether the set must be finite, or whether the list is allowed to contain repetitions) depend on the discipline of study and the context of a given problem. Some sets can be enumerated by means of a natural ordering (such as 1, 2, 3, 4, ... for the set of positive integers), but in other cases it may be necessary to impose a (perhaps arbitrary) ordering. In some contexts, such as enumerative combinatorics, the term ''enumeration'' is used more in the sense of ''counting'' – with emphasis on determination of the number of elements that a set contains, rather than the production of an explicit listing of those elements. Combinatorics In combinatorics, enumeration means counting, i.e., determining the exact number of elem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
