Imperative programming - Wikipedia. In computer science, imperative programming is a programming paradigm that uses statements that change a program's state. In much the same way that the imperative mood in natural languages expresses commands, an imperative program consists of commands for the computer to perform. Imperative programming focuses on describing how a program operates. The term is often used in contrast to declarative programming, which focuses on what the program should accomplish without specifying how the program should achieve the result. Imperative and procedural programming. The terms are often used as synonyms, but the use of procedures has a dramatic effect on how imperative programs appear and how they are constructed. Heavily- procedural programming, in which state changes are localized to procedures or restricted to explicit arguments and returns from procedures, is a form of structured programming. From the 1. 96. 0s onwards, structured programming and modular programming in general have been promoted as techniques to improve the maintainability and overall quality of imperative programs. The concepts behind object- oriented programming attempt to extend this approach. A programmer can often tell, simply by looking at the names, arguments, and return types of procedures (and related comments), what a particular procedure is supposed to do, without necessarily looking at the details of how it achieves its result. At the same time, a complete program is still imperative since it fixes the statements to be executed and their order of execution to a large extent. Rationale and foundations of imperative programming. From this low- level perspective, the program state is defined by the contents of memory, and the statements are instructions in the native machine language of the computer. Higher- level imperative languages use variables and more complex statements, but still follow the same paradigm. Recipes and process checklists, while not computer programs, are also familiar concepts that are similar in style to imperative programming; each step is an instruction, and the physical world holds the state. Since the basic ideas of imperative programming are both conceptually familiar and directly embodied in the hardware, most computer languages are in the imperative style. Assignment statements, in imperative paradigm, perform an operation on information located in memory and store the results in memory for later use. High- level imperative languages, in addition, permit the evaluation of complex expressions, which may consist of a combination of arithmetic operations and function evaluations, and the assignment of the resulting value to memory. Looping statements (as in while loops, do while loops, and for loops) allow a sequence of statements to be executed multiple times. Loops can either execute the statements they contain a predefined number of times, or they can execute them repeatedly until some condition changes. Tell him how you feel. Have a quiet word with her about it. Stay at home and rest up. Get some sleep and recover. Here you can find worksheets and activities for teaching Imperatives to kids, teenagers or adults, beginner intermediate or advanced levels. Conditionalbranching statements allow a sequence of statements to be executed only if some condition is met. Otherwise, the statements are skipped and the execution sequence continues from the statement following them. Unconditional branching statements allow an execution sequence to be transferred to another part of a program. These include the jump (called goto in many languages), switch, and the subprogram, subroutine, or procedure call (which usually returns to the next statement after the call). Early in the development of high- level programming languages, the introduction of the block enabled the construction of programs in which a group of statements and declarations could be treated as if they were one statement. This, alongside the introduction of subroutines, enabled complex structures to be expressed by hierarchical decomposition into simpler procedural structures. Many imperative programming languages (such as Fortran, BASIC, and C) are abstractions of assembly language. In these languages, instructions were very simple, which made hardware implementation easier, but hindered the creation of complex programs. FORTRAN, developed by John Backus at International Business Machines (IBM) starting in 1. FORTRAN was a compiled language that allowed named variables, complex expressions, subprograms, and many other features now common in imperative languages. The next two decades saw the development of many other major high- level imperative programming languages. Imperative meaning, definition, what is imperative: extremely important or urgent. In this lesson, you will learn how to give commands, which is also known as the imperative mood. Imperative definition, absolutely necessary or required; unavoidable: It is imperative that we leave.In the late 1. 95. ALGOL was developed in order to allow mathematical algorithms to be more easily expressed, and even served as the operating system's target language for some computers. MUMPS (1. 96. 6) carried the imperative paradigm to a logical extreme, by not having any statements at all, relying purely on commands, even to the extent of making the IF and ELSE commands independent of each other, connected only by an intrinsic variable named $TEST. COBOL (1. 96. 0) and BASIC (1. English. In the 1. Pascal was developed by Niklaus Wirth, and C was created by Dennis Ritchie while he was working at Bell Laboratories. Wirth went on to design Modula- 2 and Oberon. For the needs of the United States Department of Defense, Jean Ichbiah and a team at Honeywell began designing Ada in 1. The specification was first published in 1. These languages were imperative in style, but added features to support objects. The last two decades of the 2. Smalltalk- 8. 0, originally conceived by Alan Kay in 1. Xerox Palo Alto Research Center (PARC). Drawing from concepts in another object- oriented language. C++ was first implemented in 1. In the late 1. 98. Perl, released by Larry Wall in 1. Python, released by Guido van Rossum in 1. Visual Basic and Visual C++ (which included Microsoft Foundation Class Library (MFC) 2. Microsoft in 1. 99. PHP, released by Rasmus Lerdorf in 1. Java, released by Sun Microsystems in 1. Ruby, released by Yukihiro . Microsoft's . NET Framework (2. VB. NET and C# that run on it; however Microsoft's F#, a functional language, also runs on it. See also. Programming Languages: Design and Implementation, 3rd ed. Englewood Cliffs, N. J.: Prentice Hall, 1. Sebesta, Robert W. Concepts of Programming Languages, 3rd ed. Reading, Mass.: Addison- Wesley Publishing Company, 1. Originally based on the article 'Imperative programming' by Stan Seibert, from Nupedia, licensed under the GNU Free Documentation License.
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