There are certain tasks in C programming and other languages like PHP, what can only be done with pointers, like reading from a file requires a file pointer. Also to have a good understanding of pointers can give a great confidence to start improving the memory usage with decreasing the value duplication in programs. A pointer is an address of a memory location where an actual value is stored. Every variables memory location can be accessed by using the ‘&’ am-percent.

Structures in c are used to represent data what have connections to each other in a single variable. This could be a record from a database. Structures can be declared outside the functions to give access for all the function in the program. Other options for declaration is in the main header file(good idea), or inside main or other function which would make it available only for local use. A good practice is to not only declare the structure by create a type of that structure.

I think to have a decent understanding of c, or start learning c programming is really good even if somebody is not planning to work with the language itself. Most of the languages are based on c or are in some way related to it. Most of the currently used popular languages have at least the syntax related to c. This book can give a really great start on understanding and writing basic c functions.

If c is not your first language, you will really miss boolean primitive type. In other languages boolean is already defined, but in c there is no such type, it is actually using integer values instead. It is really simple to implement a boolean value with typedef: Other option is to include stdbool.h. Using typedef as an alias makes code more readable. The example above shows that accessing the values is along the same rules as using struct.

In the C programming language variables are declared before the program itself starts, before functionality. This applies to functions also. With an example: The following program declares c primitive data types and pointer data types and does print the size for them too.