Adding and Subtracting within pages.

[LuigiLA]

Hello everyone,

 

I am not a php programmer, but I would like to solve a problem regarding math with PHP. I was looking around on the web on how to add (in this case digits) using PHP.

I found out that adding two strings using a . I can then echo out the results; so far so good.

My question however is as follow. How do I add up information from multiple pages? Let's say on one page (let's call it weekly.php) I have my weekly expenses of $300, and on the second page (let's call it monthly.php) I have my monthly expenses of $1400. I would like the result (weekly + monthly) to be displayed (echo'ed out) on the third page (let's call it totalamount.php).

 

I don't want to take advantage of anyone's time, so I am not asking for the entire solution (code) unless you want to  , but I would be just happy to be pointed in the right direction, I will do the rest on my own.

 

Thank you very much for your time.

 

Cheers,

 

Luigi

[The Little Guy]

how are you getting these numbers(The 300 and 1400)? from a: form, database, other?

[xyph]

To elaborate on the above post, are these values hard coded into an html page? Or are they being submitted through a form?

[LuigiLA]

how are you getting these numbers(The 300 and 1400)? from a: form, database, other?

 

I am getting the number from just plain text. Imagine it's like in Excel, when using SUM=(A1+A2). By manually change A1 the SUM will adjust accordingly.

There is no database attached to this.

[LuigiLA]

To elaborate on the above post, are these values hard coded into an html page? Or are they being submitted through a form?

 

Yes, hard coded. I manually change the number on Page 1 and 2. I just want to be able to get the sum of them on the third page automatically using php.

[xyph]

You could use PHP to scrape both pages for the number, but that's a slow process that you can avoid.

 

Are you interested in doing this the right way, which will be a little more work, but make updating easier?

 

Would you prefer the quick n dirty way, and not have to change the way those other two pages are set up?

[LuigiLA]

You could use PHP to scrape both pages for the number, but that's a slow process that you can avoid.

 

Are you interested in doing this the right way, which will be a little more work, but make updating easier?

 

Would you prefer the quick n dirty way, and not have to change the way those other two pages are set up?

 

If there is a right away, I wouldn't mind using it. I am open to suggestions. It's not something urgent, so there is no rush to finish it up quickly.

Thanks!

[xyph]

Okay, well, we're going to use a text file to store our information. This is generally called a flat-file database.

 

Create a new text file, and type the two numbers in it, separated by commas. To make things as simple as possible, put the file in the same directory as the 3 files that need to use the information.

 

numbers.txt

500,1200

 

You can then use PHP to open this text file, grab it's contents and put them into a variable, split that variable up using the comma, and add, or simply output the data.

 

samplefile.php

<?php

// This will attempt to grab the contents of 'numbers.txt' and put it into $raw_data
$raw_data = file_get_contents( 'numbers.txt' );

// If file_get_contents() fails, it will return FALSE.
// We use an 'if' conditional statment to check if this has happened
if( $raw_data == FALSE ) {
// If it failed, we abort the script and output an error message
die( 'Could not get data from text file!' );
}

// If the scrip has made it this far, we know file_get_contents() grabbed the data
// successfully. We can now use the 'explode' function to split it up by the comma
$data = explode( ',', $raw_data );

// $data now holds an array, where $data[0] is the first value, $data[1] is the second value
// and $data[2] would be the third value, if we had it, and so on.

// We'll now output the data we have
echo 'The first value is '.$data[0].'<br>';
echo 'The second value is '.$data[1].'<br>';
echo 'The sum of the values is '.($data[0]+$data[1]).'<br>';
echo 'We can also use array functions to automatically add them: '.array_sum($data);

?>

 

So you'd include similar code in all 3 files, and either echo the value you want or add them up and echo them.

 

To make it even more streamlined, you could create a single file that populates $data, and use include to simply add the code to each of your files, then echo out the information you need.

[LuigiLA]

xyph, I can't thank you enough for your time.    This works perfectly for what I want to do.

Thank you so much!!!