C++ is a statically typed, compiled, general-purpose, case-sensitive, free-form programming language that supports procedural, object-oriented, and generic programming.
C++ is regarded as a middle-level language, as it comprises a combination of both high-level and low-level language features.
C++ was developed by Bjarne Stroustrup starting in 1979 at Bell Labs in Murray Hill, New Jersey, as an enhancement to the C language and originally named C with Classes but later it was renamed C++ in 1983.
C++ is a superset of C, and that virtually any legal C program is a legal C++ program.
Note − A programming language is said to use static typing when type checking is performed during compile-time as opposed to run-time.
Characteristics of C++
C++ is not a purely object-oriented language but a hybrid that contains the functionality of the C programming language. This means that you have all the features that are available in C:
■ universally usable modular programs
■ efficient, close to the machine programming
■ portable programs for various platforms.
The large quantities of existing C source code can also be used in C++ programs. C++ supports the concepts of object-oriented programming (or OOP for short), which are:
■ data abstraction, that is, the creation of classes to describe objects
■ data encapsulation for controlled access to object data
■ inheritance by creating derived classes (including multiple derived classes)
■ polymorphism (Greek for multiform), that is, the implementation of instructions that can have varying effects during program execution.
Various language elements were added to C++, such as references, templates, and exception handling. Even though these elements of the language are not strictly object-oriented programming features, they are important for efficient program implementation.
Traditional Procedural Programming
In traditional, procedural programming, data and functions (subroutines, procedures) are kept separate from the data they process. This has a significant effect on the way a program handles data:
■ The programmer must ensure that data are initialized with suitable values before use and that suitable data are passed to a function when it is called
■ If the data representation is changed, e.g. if a record is extended, the corresponding functions must also be modified.
Both of these points can lead to errors and neither support low program maintenance requirements.
Objects
Object-oriented programming shifts the focus of attention to the objects, that is, to the aspects on which the problem is centered. A program designed to maintain bank accounts would work with data such as balances, credit limits, transfers, interest calculations, and so on. An object representing an account in a program will have properties and capacities that are important for account management. OOP objects combine data (properties) and functions (capacities). A class defines a certain object type by defining both the properties and the capacities of the objects of that type. Objects communicate by sending each other “messages,” which in turn activate another object’s capacities.
Advantages of OOP
Object-oriented programming offers several major advantages to software development:
■ reduced susceptibility to errors: an object controls access to its own data. More specifically, an object can reject erroneous access attempts.
■ easy re-use: objects maintain themselves and can therefore be used as building blocks for other programs .
■ low maintenance requirement: an object type can modify its own internal data representation without requiring changes to the application.
Use of C++
C++ is used by hundreds of thousands of programmers in essentially every application domain.
C++ is being highly used to write device drivers and other software that rely on direct manipulation of hardware under real time constraints.
C++ is widely used for teaching and research because it is clean enough for successful teaching of basic concepts.
Anyone who has used either an Apple Macintosh or a PC running Windows has indirectly used C++ because the primary user interfaces of these systems are written in C++.
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