pointeur cpp
Here is an explanation of each step for using a pointer in C++:
Declaration: Declare a pointer variable of the desired data type. For example, to declare a pointer to an integer, you would use the syntax:
int* ptr;
Initialization: Initialize the pointer variable by assigning it the address of another variable. This is done using the address-of operator
&
. For example, to initialize the pointerptr
with the address of an integer variablenum
, you would use the syntax:ptr = #
Dereferencing: Access the value stored at the memory address pointed to by the pointer using the dereference operator
. For example, to access the value stored at the address pointed to by
ptr
, you would use the syntax:ptr
Assignment: Assign a value to the memory location pointed to by the pointer using the dereference operator
. For example, to assign a value of
10
to the memory location pointed to byptr
, you would use the syntax:ptr = 10;
Null Pointer: A null pointer is a special value that indicates that the pointer is not pointing to a valid memory address. It is often used to indicate the absence of a valid address. You can assign a null value to a pointer using the syntax:
ptr = nullptr;
Dynamic Memory Allocation: Use the
new
keyword to dynamically allocate memory on the heap. This is useful when you need to allocate memory at runtime. For example, to allocate memory for an integer on the heap and assign its address to a pointerptr
, you would use the syntax:ptr = new int;
Deallocation: Use the
delete
keyword to deallocate memory that was previously allocated usingnew
. This is important to prevent memory leaks. For example, to deallocate the memory pointed to byptr
, you would use the syntax:delete ptr;
Pointer Arithmetic: Pointers can be incremented or decremented to point to different memory locations. This is useful when working with arrays or iterating over a range of memory. For example, to increment the pointer
ptr
to point to the next integer in an array, you would use the syntax:ptr++;
Remember to use pointers carefully to avoid undefined behavior, such as accessing memory that has been deallocated or uninitialized.