0
What else can I help you with?
In pointers what is the use of pointer variable?
Pointer is a variable that stores the address of another variable . So pointer basically stores the address of another variable and size of pointer can be evaluated by using sizeof operator.
Definition of pointer in C?
In C programming, a pointer is a variable that stores the memory address of another variable. Pointers allow for indirect access to the value stored at the memory location pointed to by the pointer. They are commonly used for dynamic memory allocation, as well as for passing arguments to functions by reference. Pointers are declared using the '' operator, and the value stored in a pointer can be accessed using the '' operator as well.
How can an individual structure member be accessed in terms of its corresponding pointer variable?
By dereferencing the pointer variable. This can be achieved in two ways: typedef struct s { int i; float f; }; void f (struct s* p) { int x = p->i; /* using pointer to member operator */ float y = (*p).f; /* using dereference operator */ } The two methods are functionally equivalent.
Does mentioning the array name gives the base address in all the contexts?
Mentioning the array name in C or C++ gives the base address in all contexts except one. Syntactically, the compiler treats the array name as a pointer to the first element. You can reference elements using array syntax, a[n], or using pointer syntax, *(a+n), and you can even mix the usages within an expression. When you pass an array name as a function argument, you are passing the "value of the pointer", which means that you are implicitly passing the array by reference, even though all parameters in functions are "call by value". There is, however, one very important distinction. While an array name is referentially the same as a pointer, it is not a pointer in that it does not occupy program referential space in the process. This means that, while you can change the value of a pointer, and thus the address to which it points, you can not change the value of an array name. This distinction is what we call R-Value (array or pointer) as opposed to L-Value (pointer only), i.e. can the object appear on the left sign of an assignment operator.
How can you access an array without using the suffix operator?
An array's name implicitly converts to a pointer to the first element of the array at the slightest provocation. Thus to access the first element of the array, the array name suffices. To access any other element in the array without using the suffix operator, use offset pointer arithmetic. For example: int a[] = {2, 4, 6, 8, 10}; int b; b = *(a+3); assert (b == 8); Here, (a+3) points to the 4th element (offset 3). Dereferencing this address returns the value of that element, in this case 8.
What is pointer and pointer types and uses of pointer and the meaning of pointer?
The main advantages of using pointers are 1.) Function cannot return more than one value. But when the same function can modify many pointer variables and function as if it is returning more than one variable. 2.) In the case of arrays, we can decide the size of the array at runtime by allocating the necessary space. C has a minimum number of fundamental data types - a single character, a single integer or float, and a few derived data types such as a structure, an enumerated list, and an array. If you want to do much more than that, you make use of pointers. Pointers allow you to dynamically request memory to store off information for use later. They allow you to create linked lists and other algorithmically oriented data structures.
What is an array of pointers to pointers?
A pointer is a variable that stores value of address of a variable. Since a pointer itself is a variable, it is allocated a memory location.Pointer to pointer means a pointer which points to the address of a pointer. In other words a pointer to a pointer has the address of the address of a variable.We can have pointers to int, and pointers to char, and pointers to any structures we've defined, and in fact pointers to any type in C, it shouldn't come as too much of a surprise that we can have pointers to other pointers. If we're used to thinking about simple pointers, and to keeping clear in our minds the distinction between the pointer itself and what it points to, we should be able to think about pointers to pointers, too, although we'll now have to distinguish between the pointer, what it points to, and what the pointer that it points to points.
Why pointer is used to reference a string of characters write C plus plus statements that display the text hello using pointer to a string notation?
We use a pointer to reference a string because a string is an array of characters where every element is a char (or a wchar_t if using UNICODE strings). Passing arrays by value would require the entire array to be copied, but passing a pointer variable to an array only copies the pointer, which is effectively the same as passing the array by reference. #include <iostream> int main() { char * psz = "hello"; // pointer to a null-terminated string. std::cout << psz; // pass the pointer (by value) to the insertion operator. return( 0 ); }
What are the important applications of pointer?
the execution time of programe is fast using the pointer
Why pointers are known as non linear data structure?
Pointers are not structures, non-linear or otherwise. A pointer is a variable that holds a memory address. The primary operation that may be performed upon a pointer is the dereference operator, which allows indirect access to the value stored at the memory address held by the pointer variable. Pointer arithmetic may also be applied to pointers, such that the memory address stored in the pointer may be incremented or decremented in units equal to the size of the pointer's type. Thus a pointer to int where sizeof(int) is 4 would increment or decrement in units of 4 bytes. This pointer arithmetic makes it possible for a pointer to randomly access any element in a contiguous sequence of elements (such as an array) in constant time, thus allowing both linear and non-linear access to those elements. Pointers may also be used to provide links between elements that are stored non-contiguously, thus making it possible to create complex structures such as linked lists, trees, graphs and so on. This is achieved by using a node object to contain the element along with one or more links to other nodes in the sequence, both linearly and non-linearly.
What is a null macro what is the difference between a null pointer and a null macro?
NULL Macro is simply what is defined as 0 in a macro provided by the libraryNull pointer is a pointer which has 0 or NULL value stored and points to nowhwere still it points to 0x00 i.e. the first memory location of the OSNull pointer != Uninitialized pointer because an uninitialised pointer can point anywhere in the memory location ...but a NULL pointer surely points to no where(but still behind the scene we can say that it only points to 0x00). Never we can retrive a Null pointer location using th"&" operator..neither will malloc/calloc return NULL IF THERE IS SPACE IN THE MEMORY. NULL pointer is unique !!nishantnitb@aol.com
What is the relationship between an array and a pointer?
All variable names are an alias for the value stored at the memory address allocated to them. To get the memory address itself, you must use the address of operator (&). The value returned from this can then be stored in a pointer variable.Arrays are different. The array name is an alias for the start address of the array, thus you do not need the address ofoperator to obtain the memory address (although you can if you want to). This means that when you pass an array name to a function, you pass the memory address of the array rather than passing the array itself (which would require the entire array to be copied, which is a highly inefficient way to pass an array). In essence, the array is passed by reference rather than by value.Consider the following code. This shows how a primitive variable name differs from the name of an array of primitive variables. The final portion shows how a pointer can be used to achieve the same results you got by accessing the array elements directly from the array name itself. This is in fact how the compiler implements arrays, using pointers, but there's no need to do this in your code. Accessing array elements directly by their index is a programming convenience.#include using namespace std;int main(){int i = 10;cout
