introduction to scripting language

Unit 1-introduction to scripts from sana mateen

calculator database using php

Hi all this post explains implementation of calculator database in php
you are required to write the following set of instructions here.


<TITLE>PHP Calculator v1</TITLE>
<form name="calc" action="?page=calc" method="POST"> <!--implementing pagination with the page name appended to url -->
Number 1: <input type=text name=value1><br>
Number 2: <input type=text name=value2><br>
Operation: <input type="submit" name=oper value="add"/> <input type="submit" name=oper value="subtract"/>
<input type="submit" name=oper value="divide"/> <input type="submit" name=oper value="multiply"/><br>
</form>

<?php
if($_SERVER['REQUEST_METHOD'] === 'POST')//checking if the form method is post
{
$page = $_GET['page'];  
// Defining the "calc" class
class calc {
var $number1;  //variable declaration
var $number2;  
function add($number1,$number2)  {
$con=db();       //creating connection variable            
$result =$number1 + $number2;
echo("The sum of $number1 and $number2 is $result<br><br>");
echo("$number1 + $number2 = $result");
mysqli_query($con,"insert into plus values('$number1 + $number2',$result)");
exit;            
}  
function subtract($number1,$number2)  {
$con=db();                  
$result =$number1 - $number2;
echo("The difference of $number1 and $number2 is $result<br><br>");
echo("$number1 &#045 $number2 = $result");
mysqli_query($con,"insert into plus values('$number1 - $number2',$result)");
exit;          
 }  
function divide($number1,$number2)  {
$con=db();                  
$result =$number1 / $number2;
echo("$number1 divided by $number2 is $result<br><br>");
echo("$number1 &divide $number2 = $result");
mysqli_query($con,"insert into plus values('$number1 / $number2',$result)");
exit;          
 }  
function multiply($number1,$number2)  {
$con=db();                  
$result =$number1 * $number2;
echo("The product of $number1 and $number2 is $result<br><br>");
echo("$number1 x $number2 = $result");
mysqli_query($con,"insert into plus values('$number1 * $number2',$result)");
exit;            
}
}
$calc = new calc();
 ?>

<?php
if($page == "calc"){
$n1 = $_POST['value1'];
$n2 = $_POST['value2'];
$number1=abs(ltrim($n1,''));
$number2=abs(ltrim($n2,''));
$oper = $_POST['oper'];
function db () {
static $con;
if ($con===NULL){        
$con = mysqli_connect ("localhost", "root", "", "plus");
     }
return $con;
 }
if(!$number1){
echo("You must enter number 1!");
exit;    
 }
if(!$number2){
echo("You must enter number 2!");
exit;      
}
if(!$oper){
echo("You must select an operation to do with the numbers!");
exit;      
}
if(!preg_match("/[0-9]/", $number1)){
echo("Number 1 MUST be numbers!");
exit;      
}
if(!preg_match("/[0-9]/", $number2)){
echo("Number 2 MUST be numbers!");
exit;      
}
if($oper == "add"){          
$con=db();
$query = mysqli_query($con,"SELECT * FROM plus WHERE exp='$number1 + $number2'");
if (!$query) {
        echo 'MySQL Error: ' . mysqli_error();
        exit;
    }
$numrows = mysqli_num_rows($query);
if ($numrows == 0) {
$calc->add($number1,$number2);
      }

}
if($oper == "subtract"){
$con=db();
$query = mysqli_query($con,"SELECT * FROM plus WHERE exp='$number1 - $number2'");
$numrows = mysqli_num_rows($query);
if ($numrows == 0) {        
$calc->subtract($number1,$number2);
      } }
if($oper == "divide"){
$con=db();
$query = mysqli_query($con,"SELECT * FROM plus WHERE exp='$number1 / $number2'");
$numrows = mysqli_num_rows($query);
if ($numrows == 0) {  
          $calc->divide($number1,$number2);    
 }
}
 if($oper == "multiply"){
$con=db();
$query = mysqli_query($con,"SELECT * FROM plus WHERE exp='$number1 * $number2'");
$numrows = mysqli_num_rows($query);
if ($numrows == 0) {  
          $calc->multiply($number1,$number2);       } }
while ($row = mysqli_fetch_assoc($query)) {
print("Accessed from database.......<br>");
print($row['exp'] . " = " . $row['res']);
 }    
}
}
?>