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==Define three variables and use assignment operator to assign value==

<source lang="cpp">int main()
{
int term; /* term used in two expressions */
int term_2; /* twice term */
int term_3; /* three times term */
term = 3 * 5;
term_2 = 2 * term;
term_3 = 3 * term;
return (0);
}</source>

==How to declare a variable==

A variable declaration serves three purposes:
<OL><LI>It defines the name of the variable.</LI><LI>It defines the type of the variable (integer, real, character, etc.).</LI><LI>It gives the programmer a description of the variable.</LI></OL>

<source lang="cpp">int answer; /* the result of our expression */</source>
<OL><LI>The keyword int tells C that this variable contains an integer value.</LI><LI>The variable name is answer.</LI><LI>The semicolon (;) marks the end of the statement.</LI><LI>The comment is used to define this variable for the programmer.</LI></OL>

==Initialize int value in declaration ==

<source lang="cpp">#include <stdio.h>
int main(void)
{
int number0 = 10, number1 = 40, number2 = 50, number3 = 80, number4 = 10;
int number5 = 20, number6 = 30, number7 = 60, number8 = 70, number9 = 110;
int sum = number0 + number1+ number2 + number3 + number4+
number5 + number6 + number7 + number8 + number9;
float average = (float)sum/10.0f;
printf("\nAverage of the ten numbers entered is: %f\n", average);
return 0;
}</source>
<pre class=codeResult>Average of the ten numbers entered is: 48.000000</pre>

==Meaningful variable name==

<source lang="cpp">int p,q,r;</source>

==Use printf to output variable==

<source lang="cpp">#include <stdio.h>

int main()
{
int term; /* term used in two expressions */
term = 3 * 5;
printf("Twice %d is %d\n", term, 2*term);
printf("Three times %d is %d\n", term, 3*term);
return (0);
}</source>
<pre class=codeResult>Twice 15 is 30
Three times 15 is 45</pre>
The number of %d conversions should match the number of expressions.

==Using a variable to store value==

<source lang="cpp">#include <stdio.h>
int main(void)
{
int salary;
salary = 10000;
printf("My salary is %d.", salary);
return 0;
}</source>
<pre class=codeResult>My salary is 10000.</pre>

==Variables==

<OL><LI>You can store values in variables.</LI><LI>Each variable is identified by a variable name.</LI><LI>Each variable has a variable type.</LI><LI>Variable names start with a letter or underscore (_), followed by any number of letters, digits, or underscores.</LI><LI>Uppercase is different from lowercase, so the names sam, Sam, and SAM specify three different variables.</LI><LI>The variables are defined at the begining of the block.</LI></OL>
The following is an example of some variable names:

<source lang="cpp">average /* average of all grades */
pi /* pi to 6 decimal places */
number_of_students /* number students in this class */</source>

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