Pointer & Reference in C

What is a Pointer ? 

A Pointer is a variable whose value is the address of another variable, or direct address of the memory location. Like any variable or constant, you must declare a pointer before using it to store any variable address. 
 
Format :   type *var-name;

• type is the pointer's base type; it must be a valid C data type 

• var-name is the name of the pointer variable. 

• The asterisk (*) used to declare a pointer

   Example of a Valid format : 

  - int    *ip;    /* pointer to an integer */
  - double *dp;    /* pointer to a double */
  - float  *fp;    /* pointer to a float */
  - char   *ch     /* pointer to a character */ 

  Example How To Use a Pointer:

  

  Relation Between Pointer and Array 

  •  An array name is a constant pointer to the first element of the array.

     Example :

  

  
  

  •  Once we have the address in p,

           *p will give us the value available at the address stored in p

  Relation Between Pointer and Function  

  • C programming allows passing a pointer to a function. 

    We just need to declare the function parameter as a pointer type.

    here is an example where we pass a pointer to a function 
    and change the value inside the function which reflects back in the 
    calling function 

  source : www.tutorialspoint.com

  Reference

  Theres also one more kind of passing, called Passing By Reference

  Basically, A reference is an alias for another variable

  the syntax/ Format for this Reference is :

  'type &variable' and it only works on c++ compiler

  Heres what i learned For Example :