The document explains dynamic memory allocation in C++, detailing how to allocate and deallocate memory using 'new' and 'delete' operators. It provides syntax examples for creating object pointers and emphasizes the importance of matching data types between the allocated memory and the pointer. Additionally, it discusses the use of 'const' in pointer types, illustrating how it impacts the mutability of the pointer and the value it references.

1. Author – Subhasis Nayak

2.  It means a program can obtain required
memory at runtime. Run time means when
the program starts executing not compile
time.
 In C++ for dynamic memory allocation we
have two uninary operators.
◦ New
◦ Delete

3.  It is used to allocate the memory space when
ever required.
 It is also used to create objects of all types,
including a class name.
 You can allocate memory to a pointer only at
runtime. Syntax is:
◦ Pointer-variable = new data-type
 the data type may be a valid C++ data type
 Pointer-variable is a pointer of type data-type

4.  The type of allocating memory must be same to
the receiving pointer. it means, you can allocate
only integer type memory to an integer type
pointer.
Int *p = new int; Int *p = new char;
correct incorrect

5.  To assign value to a pointer we have to pass a
value using “( )” .
 Syntax will be:
◦ *p =100;
int *p =new int;
*p =200 int *p =new int(200);

7.  When an object, is not in use we must free the
memory captured by that object. So to free the
captured memory is done by “delete” operator.
 The syntax is:
◦ Delete pointer-variable.
Int *p = new int;
----;
----;
delete *p;

8.  We can use the keyword const for pointers
before the type, after the type, or in both
places. For example, all the following
declarations are legal:
◦ const int * p;
◦ int * const q;
◦ const int * const r;
 Each of the above having different meaning
and different tasks.

9.  *p is a pointer to a constant integer. The
value that is pointed to can‟t be changed.
 We can say the int pointed to a constant.

10.  „q‟ is a constant pointer to an integer. The
integer can be changed, but „q‟ can‟t point to
anything else.
 „q‟ is constant, it can‟t point to anything else.

11.  „r‟ is a constant pointer to a constant integer.
The value that is pointed to can‟t be changed,
and „r‟ can‟t be changed to point to anything
else.