| calculating from a dynamic form
calculating forms math arrays |
sades
msg:3878477 | 2:47 pm on Mar 25, 2009 (gmt 0) |
Hello all im new to the forum and kind of new to php im trying to do this but cant figure out how i have a page with a dynamic form wich extracts info from a table id
title
price on the form i have a repeat all which will display the title, price and id of each item, and a text box which i added id= <?php $id; ?> and also the internal name this text box will ask the user for an amount what i need to do is that this amount be multiply by the price and then do a sum of all of it, i have manage to show the amount in a $_POST[$id] but i have no idea how to do the multiplication and then the sum, i donīt need to save the data from the post in a database just show the person that is using this what he has to pay if he adds X amounts of products, i was thinking on using arrays but im still to new to php trying to learn any helps is appreciated Thanks
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wheelie34
msg:3878585 | 4:55 pm on Mar 25, 2009 (gmt 0) |
Hi sades and welcome to the forum Maths is fairly simple in php, for example $answer = ( $a x $b );# multiply
$answer = ( $a - $b );# subtract
$answer = ( $a + $b );# add
$answer = ( $a / $b );# divide HTH
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d40sithui
msg:3878633 | 5:46 pm on Mar 25, 2009 (gmt 0) |
You need to save your item id, and your item amount(which the user enters) in an array. Then loop through the array, find the price for each item (using a query with the item id stored), and then multiply that with the amount - also stored in the array.
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sades
msg:3878644 | 5:53 pm on Mar 25, 2009 (gmt 0) |
thanks for the replays on the math part i have no problems what i dunno how to do is save the variable in the post (amount) in an arrays and then do the amount*price thing for each element of the array any tips?
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whoisgregg
msg:3878656 | 6:12 pm on Mar 25, 2009 (gmt 0) |
Btw, multiplication uses the asterisk "*" not the lower case "x" ;)
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d40sithui
msg:3878670 | 6:35 pm on Mar 25, 2009 (gmt 0) |
<your form will probably look something like this>
<form action="index.php" method="POST">
Item1<input type="text" name="item1"><br>
Item2<input type="text" name="item2"><br>
Item3<input type="text" name="item3"><br>
<input type="submit" value="submit">
</form>
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<inside your action script>
$total = 0;
foreach(array_keys($_POST) as $key){ //assigns variables
$itemId = str_replace("item", "", $key); //takes off the "item" to reveal the item id
$amount = $_POST[$key]; //checks for invalid data - i.e not integer inputs //query for price of item
$result = mysql_query("SELECT price FROM myItemsTable where id = ".$itemId);
$row = mysql_fetch_assoc($result);
$price = $row['price']; //total price for this item
$subTotal = $price*$amount; //grant total
$total+=$total;
}
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