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A pointer is a variable that can store a reference (a memory address) or can store a NULL value (zero). The only use of any pointer in C++ is whenever you need to refer to memory that, for whatever reason, may not be valid. That is, if there is any possibility that a reference could be NULL, then you must use a pointer, because NULL references are invalid in both C and C++.



By way of an example, when you dynamically instantiate a new object at runtime, there is no way to guarantee that a sufficient block of free memory will be available, therefore you cannot reference that memory. For that reason, the new operator returns a pointer, not a reference. This is no different to the way the malloc() function returns a pointer, not a reference, in C.


As well as dynamic allocations, pointers can also be used to pass objects to functions. While programmers are encouraged to pass objects by reference rather than by value, it is sometimes desirable to pass a NULL reference. But since references can never be NULL, a NULL pointer must be passed instead.


Since pointers are variables they are more flexible than references insofar as once a memory address is assigned to a reference, that reference cannot refer to any other memory address while it remains in scope. But pointers can be assigned to point at any reference, including a NULL reference, at any time.



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Q: What are Uses of pointer in c plus plus?
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Related questions

What is Dazzling Pointer in c plus plus?

The pointer that points to a block of memory that does not exist is called a dazzling pointer or wild pointer


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generic pointer is a pointer that can not be dereferenced i.e one type pointer can not be assigned to another type.


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Address of the current object.


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Yes, C++ supports function pointers.


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Accessing data by address.


What is null object in c plus plus?

a pointer that is not pointing to anything


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An address in C or C++ is the location in memory of an object or function. An address is the contents of a pointer, as opposed to the contents of the memory location pointed to by the pointer.


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A pointer is an object that contains the address of another object, hence the term pointer, meaning that one object points to another.


What does multiplying a pointer by 5 in C plus plus mean How does it change the pointer's value?

Multiplication is yet another thing, what you should never do with pointers.


Which function is used to determine the position of the put pointer in a file in c plus plus?

The function ftell returns the position of the file pointer for a file.


What is pointer in C plus plus?

A pointer is a variable that holds an address in memory. int * pPointer = new int; This code creates a pointer to an integer, and assigns it an address of an integer object on the heap.


What is this operator in C plus plus?

The this operator in C++ is a compiler generated pointer to the instance of an object, accessible from within a method of that object.


Uses of pointers?

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Indirect addressing uses a pointer. Indirectly accessing the memory being pointed at is known as dereferencing. Direct addressing uses a variable's name or a reference to obtain the value.


What is double pointer in c plus plus?

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What is called pointers-c plus plus?

A pointer in C++ is the same as a pointer in C -- it is a variable that is used to store a memory address and which allows indirect access to that memory address. When a pointer is not in use, it must be zeroed or nullified by assigning the NULL value, thus preventing indirect access to invalid memory.


What is pointer to class in c plus plus?

You cannot point at a class. Pointers are defined by the class of object they can point at. An object is an instance of a class and the pointer points at the object, not the class.


What is an iterator in c plus plus?

An iterator is a type of pointer that is used to iterate or traverse an array or list of objects.


Do you have pointer concept in c plus plus language?

Yes. All string variables are pointers as are other arrays.


How do you access memory dynamically in c plus plus?

You access memory with a pointer or a reference to the memory. To allocate memory dynamically, use calloc or malloc (C or C++) or new (C++ only).


Which operator can not be overload in c plus plus?

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What disadvantages of using pointers in c plus plus language?

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Call by reference using pointer in c plus plus?

Example: void foo( MyClass& object ){} // function with call by reference signature MyClass* p = new MyClass(); // instantiate a pointer to MyClass foo( *p ); // call by reference using the pointer


What is the concept of asterisk in c plus plus?

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Which operator not overloaded in c plus plus?

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