In the

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming ...

, and are a pair of language constructs that perform

dynamic memory allocation Memory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when ...

, object construction and

object destruction In object-oriented programming (OOP), the object lifetime (or life cycle) of an object is the time between an object's creation and its destruction. Rules for object lifetime vary significantly between languages, in some cases between implementa ...

Overview

Except for a form called the "placement new", the operator denotes a request for memory allocation on a process's heap. If sufficient memory is available, initialises the memory, calling object constructors if necessary, and returns the address to the newly allocated and initialised memory. A request, in its simplest form, looks as follows: p = new T; where is a previously declared pointer of type (or some other type to which a pointer can be assigned, such as a superclass of ). The

default constructor In computer programming languages, the term default constructor can refer to a constructor that is automatically generated by the compiler in the absence of any programmer-defined constructors (e.g. in Java), and is usually a nullary constructor. I ...

for , if any, is called to construct a instance in the allocated memory buffer. If not enough memory is available in the free store for an object of type , the request indicates failure by throwing an exception of type . This removes the need to explicitly check the result of an allocation. The deallocation counterpart of is , which first calls the destructor (if any) on its argument and then returns the memory allocated by back to the free store. Every call to must be matc