Noted down the important concepts:
1. Reference Operator (&)
ex.
myvar = 25;
foo = &myvar;
bar = myvar;
2. Dereference Operator (*)
ex.
baz = *foo;
3. Pointers & Arrays
It collects so many ways to get address from an array and set value to an array.
#include <iostream>
using namespace std;
int main ()
{
int numbers[5];
int * p;
p = numbers;
*p = 10;
p++;
*p = 20;
p = &numbers[2];
*p = 30;
p = numbers + 3;
*p = 40;
p = numbers;
*(p+4) = 50;
for (int n=0; n<5; n++)
cout << numbers[n] << ", ";
return 0;
Output:
10, 20, 30, 40, 50,
4. Pointers and Const
int x;
int * p1 = &x; // non-const pointer to non-const int
const int * p2 = &x; // non-const pointer to const int
int const * p3 = &x; // also non-const pointer to const int
int * const p4 = &x; // const pointer to non-const int
const int * const p5 = &x; // const pointer to const int
5. Pointers to Pointers
char a;
char * b;
char ** c;
a = 'z';
b = &a;
c = &b;
6. Pointers and Functions
#include <iostream>
using namespace std;
int addition (int a, int b)
{ return (a+b); }
int subtraction (int a, int b)
{ return (a-b); }
int operation (int x, int y, int (*functocall)(int,int))
{
int g;
g = (*functocall)(x,y);
return (g);
}
int main ()
{
int m,n;
int (*minus)(int,int) = subtraction;
m = operation (7, 5, addition);
n = operation (20, m, minus);
cout << n;
return 0;
}
Output:
8
Mostly, we use function point in
sqort().
7. Arrow
Same description below:
(*p).foo;
p->foo;
Ref.
http://www.cplusplus.com/doc/tutorial/pointers/
is the matrix formed by replacing the ith column of 
by the column vector 
.
