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C makes extensive use of memory pointers for the handling of a parent function calls, data structures and much more. Knowing how to work directly with pointers is the key to efficient coding C .

Create Memory Pointer Variables

Understand that the memory pointer variables always point to the data of a particular type. For example, a pointer to an int is different from a pointer to a char. However, C is not going to let them mix freely. Doing so only if you’re sure what you’re doing .

Create a pointer variable memory by using the syntax that you use to create a variable of the type you want, but with an asterisk (*) Prior to The variable name, like this:

* int x;

Consider NULL. Can always be NULL pointer (0), and this is usually used to refer to a pointer that has not yet been set for any point of reference and .

dereference

Meet reference. References refers to the process of finding a pointer to an existing variable. In C, the operator of reference is the ampersand (&). For example:

int color = 5; int * pointer_to_color; pointer_to_color = &color;

Using Dereferencing. Dereferencing is the process of following a pointer to its value, the opposite baseline. In the C asterisk (*) is used for dereferencing, as follows:

printf ( “Color is% dn,” pointer_to_color *); / * print 5 */

use memory pointer Variables

Pass in a pointer to the variable when you need a function to change a variable, instead of passing the variable value. This allows use the dereferencing to change the value:

convert_color_to_RGB vacuum (int color, red int *, int * green, blue int *) (* = redpart red (color); greenpart * = green (color); bluepart = blue (color)) convert_color_to_RGB (15, & myred, and mygreen, and myblue );

working around the limitations of the C. Every time you want to pass a matrix structure or any function, you must pass a pointer instead, because it allows only single C data types that are passed to functions:

int subtotal (int * scores, int howmany) (int total = 0, i; for (i = 0; i

Create a loop. Because the chains are actually sets of characters , You can create a pointer to a character through a loop of string:

replace_character vacuum (char * s, char from, char a) (char * cp; for (cp = s; & & * cp Cp; cp ) If (* of == cp) cp = ;}

to understand how views C arrays. The matrices are handled by pointers as C, using pointer arithmetic. C multiply that automatically align a pointer on the size of the elements pointing. This means that

scores [5] = 17;

is exactly the same as

*( scores 5) = 17 ;

. You can use pointers as shorthand for a range dereferences. For example,

* scores = 17;

always refers to the 0TH element of the array.

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