CPP

pointers in c++

/*
Here is how pointers work in a nustshell(represent | as what's
happening in the memory and / as a place in the ram):
int x = 2; | 2/0x00ef5
int *z = &x| 0x00ef5/0x00ef6 (See how the value of the pointer z
matches with the memory address of x? that's how they work!)

when you print out the pointer as *n (replace n with the var name)
it will actually look at the value
see it's a memory address
go to that memory address
and print the value originally in the memory address which is 2

Here is code:
*/
int x = 5;
int *y = &x;
cout << *y+1;
/*
the reason why i did *y+1 was so to show that after it got
the value from the memory address it will add 1
*/

pointers in c++

#include <iostream>

using namespace std;

int main()
{
   int x=5;
   int *ptr=&x;
   cout<<&x<<endl;        //prints the address of the variable (x)
   cout<<ptr<<endl;       //prints the address of the variable (x)
   cout<<*ptr<<endl;      //prints the value of x(5)
   cout<<&ptr<<endl;      //prints the address of the pointer (ptr)
   
   
}

c++ pointers and functions

#include <iostream>

using namespace std;

void increment(int *n){  		//declare argument of the functon as pointer
    *n+=1;
   cout<<"In function: "<<*n<<endl; 
}

int main()
{
   int x=5;			
   increment(&x);		//passing the address of the variable to the function
   cout<<"In main: "<<x<<endl;
   
}

c++ function as pointer

// c++ function as pointer syntax
type(*function_name)(params...){
 	// body
}

pointer c++

int myvar = 6;
int pointer = &myvar; // adress of myvar
int value = *pointer; // the value the pointer points to: 6

why do we use pointers in c++

//why do we use pointers:
1)pass values by refrence to a function
2)return multiple values from a function
3)use pointers in combinational with arrays
4)dynamic memory allocation
5)use pointers in a base class in order to access object of derived class (Smart pointers)

Pointers in c++

int x = 2;
int *y = &x;

cout << *y;

pointer in c++

// Variable is used to store value
int a = 5;
cout << a; //output is 5

// Pointer is used to store address of variable
int a = 5;
int *ab;
ab = &a; //& is used get address of the variable
cout << ab; // Output is address of variable

pointers c++

baz = *foo;

c++ define function pointer

// Here's a macro I use to define a type.
// You're welcome to use it, but I'll also show how the type is defined.
#define d_typedef_func_ty(return_z, name, ...) typedef return_z (*name)(__VA_ARGS__);
d_typedef_func_ty(int, int_2i_f, int, int); // creates a int(*)(int, int) function pointer
// which is equivelant to the following:
typedef int(*int_2i_f)(int, int);

pointer in c++

uIndex = uchCRCLo ^ *puchMsg++ ; // pointer used in varible incriment

Pointers c++

// This will explain how pointers are used
#include <iostream> 
using namespace std; 
int main() 
{     
  int a = 5;  //Declare and initialize a variable
  /*
  The following pointer declarations are all valid and they all are doing the same:
  Declaring a new pointer and initializing it with 0 (a non accessible memory address) for safety-reasons.
  int * b = 0;
  int* b = 0                 
  int *b = 0; // This is how its usually written.
  int *b; // <= this, however would cause "b" to point to some random address which might be unsafe.
  */
  int *b = 0; // Create a new pointer of type int and initialize it with 0

  cout << ""b" is initialized and now pointing to memory-address:  " << b << endl << endl;

  //Now make the pointer "point" to the address of a
  b = &a; //"b" now points to the address of "a"

  cout << ""a" is stored at memory-address:  " << &a << endl;
  cout << ""b" is stored at memory-address:  " << &b << endl;
  cout << ""b" is pointing to memory-address now:  " << b << endl << endl;

  cout << "The value of "a" is: " << a << endl;  // returns the value of a

  //the "*b" will get the value from the address b points to (the value of a)
  cout << "The value of the area "b" is pointing to is: " << *b << endl << endl << endl;

  //Now modify the value of the address "b" is pointing to...effectively changing the value of "a"     
  *b=10;

  cout << ""a" is still stored at memory-address:  " << &a << endl;
  cout << ""b" is still stored at memory-address:  " << &b << endl;
  cout << ""b" is still pointing to memory-address:  " << b << endl << endl;

  cout << "The value of "a" is now: " << a << endl;  // returns the value of a
  cout << "The value of the area "b" is pointing to is now: " << *b << endl << endl;

  return 0;        
}

pointers in c++

void simple_pointer_examples() {
    int   a;  // a can contain an integer
	int*  x;  // x can contain the memory address of an integer. 
 	char* y;  // y can contain the memory address of a char. 
 	Foo*  z;  // z can contain the memory address of a Foo object.  
 
    a = 10;
    x = &a;   // '&a' extracts address of a 
  
    std::cout <<  x << std::endl; // memory address of a => 0x7ffe9e25bffc
    std::cout << *x << std::endl; //          value of a => 10
}

how a function gives a pointer as parameter c++

//example that uses pointer as parameter

// function definition to swap the values.
void swap(int *x, int *y) {
   int temp;
   temp = *x; /* save the value at address x */
   *x = *y; /* put y into x */
   *y = temp; /* put x into y */
  
   return;
}