Wednesday, June 26, 2013

Infinite Array Problem In C#.net

You can't define C#.net arrays with an infinite array length. You must have to provide a length for the array. But there is a solution to fulfill the need of infinite arrays in C#.net.
We call it as List.

We can define a C#.net array like below,
Syntax:-
List<data_type>name_for_list=new List<data_type>();
eg:-
List<char>plainChar=new List<char>();

We can feed data to the list like below,
Syntax:- 
list_name.Add(value_needed_to_add);
eg :-
plainChar.Add('C');

We can retrieve elements from the list like below,
Syntax:- 
list_name[index_of_the_element];
eg:-
plainChar[3];

Saturday, June 8, 2013

How to POST data to a PHP script using HTML as an Array

When we work with HTML and PHP, sometimes we need to send data to a PHP script as an array. As an example consider about a food ordering page. In that case we should provide the functionality of choosing more than one food item in several quantities. If we are not supposing to do this with array, we are required to do more coding with both HTML and JavaScript. With this technique we are using only the HTML for client side and PHP for the server side.

Note : <input type="hidden"> is an important HTML form element which can hold some data to be sent to the PHP script. But they are not visible to the HTML viewers.


foodMenu.html


<form action="foodMenu.php" method="post">
<div>
        <p>Lunch</p>
        <p>
        <span><input type="hidden" value="Food Item 1 " name="itemName[]">Food Item 1
<input type="hidden" value="100" name="itemCost[]">100/=</span><br>
<input type="textbox" value="0" name="itemQTY[]">
<input type="button" value="Select" >
        </p>
        <p>
        <span><input type="hidden" value="Food Item 2" name="itemName[]">Food Item 2
<input type="hidden" value="150" name="itemCost[]">150/=</span><br>
<input type="textbox" value="0" name="itemQTY[]">
<input type="button" value="Select">
        </p>
        <p>
        <span><input type="hidden" value="Food Item 3" name="itemName[]">Food Item 3
<input type="hidden" value="150" name="itemCost[]">150/=</span><br>
<input type="textbox" value="0" name="itemQTY[]">
<input type="button" value="Select" >
        </p>
<input type="submit" value="Submit" >
 </div>


foodMenu.php


<?php   

$itemName=$_POST['itemName'];  //Grab the posted item names from the html form
$itemQTY=$_POST['itemQTY'];    //Grab the posted item QTY from the html form
$itemPrice=$_POST['itemCost'];  //Grab the posted item prices from the html form

$grandTotal=0;
echo('<table>');
echo('<tr><td>Meal List</td></tr>');
echo('<tr><td>Items</td><td>QTY</td><td>Cost</td></tr>');

for($count=0;$count<count($itemName);$count++){ //loop to print stored data in the arrays
    if($itemQTY[$count]>0){
        echo("<tr>");
        echo('<td>'.$itemName[$count].'</td><td>'.$itemQTY[$count].'</td><td>'.subTotal($itemPrice,$itemQTY,$count));
        echo("</tr>");
    }
}
echo('<tr>');
    echo('<td>'.'</td><td>'.totalQTY($itemQTY).'</td><td>'.$grandTotal.'</td>');                                             
    echo('</tr>');
echo('</table>');
//function to calculate sub totals and grand totals
function subTotal($itemPrice,$itemQTY,$count){
 global $grandTotal;  //refer to above global variable at the begining
$subTotal[$count]=$itemPrice[$count]*$itemQTY[$count];
$grandTotal=$grandTotal+$subTotal[$count];

return $subTotal[$count];

}
//function to calculate the total number of the QTYs
function totalQTY($itemQTY){
return array_sum($itemQTY);
}
?>