Variable Declaration

Variables are something like a character or word that you use to temporarily store some value.
There are specific types of data that you can store in C Language. A few of them are
integer (int), character (char), decimal number (float), etc...

There's a question in Chapter 2 Page no 89 of the book i mentioned

Code the variable declarations for each of the following:

a. a character variable named option

b. an integer variable, sum, initialised to 0

c. a floating-point variable, product, initialised to 1

Well lets see how to do it:

/*include your necessary headers*/

#include<stdio.h>

/*write your main() function*/

int main()

{

      /*Declare the character*/

      char option;

     

      /*Declare the integer*/

      int sum=0;

      /*Declare the decimal no*/

      float product;

      product=1;

      return 1;

}

You can see how we initialise the variables in two different ways.

1. You can initialise the variable while declaring it.( int sum=0; )
2. You can initialise the variable in a separate line after declaring it ( float product; product =1; )

Both will do the job!

A similar question in the same page:

Code the variable declarations for each of the following:

a. a short integer variable named code

b. a constant named salesTax initialised to .0825

c. a floating-point number sum of size double initialised to 0;

Well lets see how to do it:

/*include your necessary headers*/
#include<stdio.h>

/*write your main() function*/
int main()
{
      /*Declare the short integer*/
      short code;
     
      /*Declare the constant*/
      const float salesTax=0.0825;

      /*Declare the floating no of size double*/
      double sum;
      sum=0;

      return 1;
}

That's it! Now we can move on to the next topics.

I made a sample program to show the declaration:

No issues says that it is valid:)

Stay tuned for more!

About this site

Well this site deals exclusively with the C Programming Language! Here we take you from the basics of C to the use of few of the most important libraries that we have mastered so far.

For the Basics we refer to "Computer Science - A Structured Programming Approach Using C" by Behrouz A. Forouzan & Richard F. Gilberg. 

So all set to start?

Firstly you will need a compiler (something to run your C code).

I use XCode 4.6.3 on Mac. You can use Visual Studio or Turbo C for Windows and gedit with cc compiler on Ubuntu or Linux.

First program

Let's traditionally stick to "Hello World" program but not actually type the same you know:)

Coz when I first started programming at the age of 6 I never felt like typing the same in BASIC.

So type whatever comes to your mind inside the angle braces < >.

/*My first program*/

/*Copyright (c) 2013 Kevin Prasanna. All rights reserved.*/

/*Include Header files*/

#include <stdio.h>

/*Main function*/

int main()

{

    printf("HEY COMPUTER PRINT MY NAME : KEVIN\n");

    return 1;

}

Everything within /*_ _ _*/ is a comment line. This is essential though it doesn't add up to any code.
It shows the owner of the code and stuff like that. You will know more of its uses when we take up a little longer programs:)

NOTE: If you are using Turbo C or Visual Studio you will have to add the header file called <conio.h>
as #include <conio.h>

This is how the code looks on XCode

This is how it should look in Visual Studio

Just the run the code by pressing the play buttons.
See your output.
Comment further if you need any help in setting up XCode or Visual Studio.
Do Comment and Subscribe if you like it! Stay Tuned!