Question

Explain the use of Scope resolution Operator and Memory Management Operators in C++ with examples .

Answer 1

Use of Scope resolution Operator ( :: )
The scope resolution operator (::) is used to access the data of global version of variable. C++ is a block-structured language. Different  blocks can be used in a program. The same variable name can be used in different blocks with different values. They are stored at  different memory locations.

Example:
#include<iostream.h>
void main( )
{
int a=10; // local to main
cout<<“a=”<<a; // a=10
{
int a=25; // local to inner block
cout<<a;// a=25
cout<<::a; // a=10 outer block variable is accessed
}
}

Use of memory management operator : new and delete
The new operator is used to create objects of any type. The syntax is as follows:

Pointer_variable = new data type;

Example : p = new int; // p is pointer of type int .
The delete operator is used to destroy the variable from the  memory space so that the same space can be used for another use. The syntax of delete is as follows: 

delete pointer variable;
Example: delete p; // delete pointer variable p from memory.