C Programming Tutorial for beginners (Part 2)

In the previous tutorial we are discuses about c compiler and write a simple print program if you don’t read the tutorial then go to thislink and read the first tutorial.

Today we discusses about header file of c language and data type of c and write some program.

Header files:

• ·         stdio.h: for standardized input and output function.
• ·         conio.h: for clearing the screen.
• ·         string.h: for string handling function.
• ·         stdlib.h: for some miscellaneous.
• ·         math.h: for mathematical function.
• ·         alloc.h: for dynamic memory allocation.

Header files are system define function.

All the header files are referenced at the start of the source code file that uses one or more function from that file.

Header files are add by the flowing  #include or #include

You can’t understand the all header files works now but when we will write the program then you can easily understand where we include the proper header file.

In first tutorial we used stdio.h header file it is use to read keyboard input and output function.

Basic data type in c:

C language provides very few basic data types like Character, integer, floating point, double valueless.

Table list of data types:

Data Type	Keyword used	Size in Bytes	Range	Use
Character	char	1	-128 to +127	To store characters
Integer	int	2	-32768 to +32767	To store integer numbers
Floating Point	float	4	3.4E-38 to304E+38	To store floating point numbers
Double	double	8	1.7E-308 to 1.7E+308	To store big floating point numbers
Valueless	void	0	Valueless	--

See the table carefully and try to remember it.

Now we are write a program that display us a integer number.

#include

int main ()

{

    int num;

    num = 12;

    printf("The number is %d", num);

    return 0;

}

Output: The number is 12.

int num; its means here is a integer variable named num it’s called variable declare.

Next line we declared num = 12. So the integer number is 12.

printf function display us the number 12, %d used to display integer number.

printf(“The number is %d”, num);  hear %d is replaced by the value of num.
So the output is The number is 12.

Now we write another program that read input from the user and display it.

#include

int main ()

{

    int num;

    printf("Enter any number :");

    scanf("%d", &num);

    printf("The number is %d", num);

    return 0;

}

Output : 

Enter any number 12

The number is 12

It is same as the previous program just add two extra line.

You can see here we use a new function scanf it is used to read the keyboard intup.

%d is defined that the input must be integer number and &num the address of the integer value where the value is store.

Other code are the same as the previous program.

In the previous program we initialised  the value of num in program time and in this program the valu of num initialised in run time.

Ok that’s enough for the second day now practise this programs and modify the programs and run.

If any error in the programs feel free to comment bellow. Thanks