[SOLVED] Maths Question

[affc]

Gday,

 

Even though I am starting to get the hand of PHP i am not much when it comes to maths, so I am hoping someone else is a little more gifted in this area

 

I want to find out the difference between a number that is submitted and a number in a database and work out the difference in a positive value.

 

Eg if 6 was in the database and 14 was submitted, the difference would be 8.

 

Im thinking something like

 

 <?php
if($submitted>$database){ $submitted-$database=$result }else if($submitted<$database){ $database-$submitted=$result }
?>

 

[KevinM1]

Gday,

 

Even though I am starting to get the hand of PHP i am not much when it comes to maths, so I am hoping someone else is a little more gifted in this area

 

I want to find out the difference between a number that is submitted and a number in a database and work out the difference in a positive value.

 

Eg if 6 was in the database and 14 was submitted, the difference would be 8.

 

Im thinking something like

 

 <?php
if($submitted>$database){ $submitted-$database=$result }else if($submitted<$database){ $database-$submitted=$result }
?>

 

 

It'd be easier to just use the absolute value:

$tmp = $submitted - $database; //store the difference in a temporary variable
$result = abs($tmp); //find the absolute value of the difference and store the result

echo "$result";

 

From what I can tell by reading the manual, the abs() function can't calculate the absolute value of a mathematical expression; it can only find the value of individual numbers.  That's why you should first store the difference in a temporary variable.

[affc]

What is the submitted value is 4 and the database number is 50, that would give -54, how does this ABS turn it into +54 so I dont have the minus in it or does it do it automatically? thanx

[affc]

Actually my maths is really bad, the result would be -46 lol but still would it find out that the difference should be 54?

[affc]

Just tried it like this and worked a charm, but i dont really understand how it finds out the difference lol, it even works if I put -10, thanx

[affc]

<?php

$database="10";

$submitted="-10";

$tmp = $submitted - $database; //store the difference in a temporary variable

$result = abs($tmp); //find the absolute value of the difference and store the result

 

echo "$result";

 

?>

Result was 20 which is perfect so obviously works some how

[KevinM1]

Absolute value is simply the value of a number.  Whether it's positive or negative doesn't matter - the value of the number is the same in either case.  That's what the abs() function returns.

 

More info on absolute values: http://en.wikipedia.org/wiki/Absolute_value

[affc]

Thanx once again I also noticed my status is now Enthusiast No Guru yet

[Daniel0]

Thanx once again I also noticed my status is now Enthusiast No Guru yet

 

Heh... sorry to let you down, but "Guru" is manually assigned to people who've shown themselves worthy. You can find more info here: http://www.phpfreaks.com/forums/index.php/topic,232740.0.html