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Country calling codes, country dial-in codes, international subscriber dialing (ISD) codes, or most commonly, telephone country codes are telephone number prefixes for reaching telephone subscribers in foreign countries or areas via international telecommunication networks.
ISO 3166-1 alpha-2 codes are two-letter country codes defined in ISO 3166-1, part of the ISO 3166 standard [1] published by the International Organization for Standardization (ISO), to represent countries, dependent territories, and special areas of geographical interest.
This list comprises the world's largest companies by consolidated revenue, according to the Fortune Global 500 2024 rankings and other sources. [2] American retail corporation Walmart has been the world's largest company by revenue since 2014. [1] The list is limited to the largest 50 companies, all of which have annual revenues exceeding US ...
As of Unicode version 16.0, there are 154,998 characters with code points, covering 161 modern and historical scripts, as well as multiple symbol sets. This article includes the 1,062 characters in the Multilingual European Character Set 2 (MES-2) subset, and some additional related characters.
- Overview
- History
- Syntax
- "Hello, World" Example
- Data Types
- Memory Management
- Libraries
- Language Tools
- Uses
- Related Languages
Like most procedural languages in the ALGOL tradition, C has facilities for structured programming and allows lexical variable scope and recursion. Its static type system prevents unintended operations. In C, all executable code is contained within subroutines (also called "functions", though not strictly in the sense of functional programming). Fu...
Early developments
The origin of C is closely tied to the development of the Unix operating system, originally implemented in assembly language on a PDP-7 by Dennis Ritchie and Ken Thompson, incorporating several ideas from colleagues. Eventually, they decided to port the operating system to a PDP-11. The original PDP-11 version of Unix was also developed in assembly language. Thompson desired a programming language to make utilities for the new platform. At first, he tried to make a Fortran compiler, but soon...
K&R C
In 1978, Brian Kernighan and Dennis Ritchie published the first edition of The C Programming Language. This book, known to C programmers as K&R, served for many years as an informal specification of the language. The version of C that it describes is commonly referred to as "K&R C". As this was released in 1978, it is also referred to as C78. The second edition of the book covers the later ANSI Cstandard, described below. K&Rintroduced several language features: 1. Standard I/O library 2. lon...
ANSI C and ISO C
During the late 1970s and 1980s, versions of C were implemented for a wide variety of mainframe computers, minicomputers, and microcomputers, including the IBM PC, as its popularity began to increase significantly. In 1983, the American National Standards Institute (ANSI) formed a committee, X3J11, to establish a standard specification of C. X3J11 based the C standard on the Unix implementation; however, the non-portable portion of the Unix C library was handed off to the IEEE working group 1...
C has a formal grammar specified by the C standard. Line endings are generally not significant in C; however, line boundaries do have significance during the preprocessing phase. Comments may appear either between the delimiters /* and */, or (since C99) following // until the end of the line. Comments delimited by /* and */ do not nest, and these ...
The "hello, world" example, which appeared in the first edition of K&R, has become the model for an introductory program in most programming textbooks. The program prints "hello, world" to the standard output, which is usually a terminal or screen display. The original version was: A standard-conforming "hello, world" program is:[a] The first line ...
The type system in C is static and weakly typed, which makes it similar to the type system of ALGOL descendants such as Pascal. There are built-in types for integers of various sizes, both signed and unsigned, floating-point numbers, and enumerated types (enum). Integer type char is often used for single-byte characters. C99 added a boolean datatyp...
One of the most important functions of a programming language is to provide facilities for managing memoryand the objects that are stored in memory. C provides three distinct ways to allocate memory for objects: 1. Static memory allocation: space for the object is provided in the binary at compile-time; these objects have an extent(or lifetime) as ...
The C programming language uses libraries as its primary method of extension. In C, a library is a set of functions contained within a single "archive" file. Each library typically has a header file, which contains the prototypes of the functions contained within the library that may be used by a program, and declarations of special data types and ...
A number of tools have been developed to help C programmers find and fix statements with undefined behavior or possibly erroneous expressions, with greater rigor than that provided by the compiler. The tool lintwas the first such, leading to many others. Automated source code checking and auditing are beneficial in any language, and for C many such...
C is widely used for systems programming in implementing operating systems and embedded system applications, because C code, when written for portability, can be used for most purposes, yet when needed, system-specific code can be used to access specific hardware addresses and to perform type punning to match externally imposed interface requiremen...
C has both directly and indirectly influenced many later languages such as C#, D, Go, Java, JavaScript, Limbo, LPC, Perl, PHP, Python, and Unix's C shell. The most pervasive influence has been syntactical; all of the languages mentioned combine the statement and (more or less recognizably) expression syntax of Cwith type systems, data models, and/o...
Mission: Impossible – Dead Reckoning Part One[ a ] is a 2023 American spy action film directed by Christopher McQuarrie from a screenplay he co-wrote with Erik Jendresen. [ 7 ] . It is the sequel to Mission: Impossible – Fallout (2018) and the seventh installment in the Mission: Impossible film series.
List of tz database time zones. The tz database partitions the world into regions where local clocks all show the same time. This map was made by combining version 2023d with OpenStreetMap data, using open source software. [1] This is a list of time zones from release 2024b of the tz database. [2]
