Need help with calculating and return

General PHP Help
1

Hello all!
Got another code that I need a helpful nudge with. I need to create a function to calculate the area of a circle. The function has to take in two arguments (a number and a string). The number is the diameter; the string is the word “diameter.” The function has to return the area of the circle or a -1 for an error. The script has to initialize test variables, call the function and display the results. I’m such a noob so don’t laugh when you see my code thus far. I appreciate any help you can offer.

<? php// 
variables$diameter = 4.0;
$pi = 3.14;
$area = ($diameter * $pi);
$title = "Circle";      
   
function circle_function (4.0, "diameter")        
  if ($diameter * $pi) !=$area)      
 {         
return $area;      
  }                 
 {       
  else          
return -1;         
 }        
 if ($area == -1)        
 {        
 echo "Invalid input";   
      exit -1;        
 }                  
echo "<html>
		
<head>			
<title>			
$title			
</title>		
</head>	
<body>   
<h1>Area of a Circle</h1>\n";
      echo circle_function();     
 echo    "</body>		
	</html>";
?>
2

My code didn’t copy exactly right but it’s close. Really bad, huh? Sorry. Maybe with a little nudge, I’ll get it! ;D

3

Hi there,

I’ve quickly thrown together an example of how you might go about this - let me know if you need help understanding/modifying it.

[php]
function circle_area($num,$type=“radius”)
{
if(is_numeric($num) && is_string($type) && !empty($num) && !empty($type))
{
$radius = ($type == “diameter”) ? $num/2 : $num; // Radius is set to half the given number if the type is diameter, or unchanged if radius
$area = pi()*pow($radius,2); // Pi as defined by php multiplied by radius to the power of 2 (squared)
return $area; // Return result
}
else
{
return -1; // Return Pi when invalid/empty values are given
}
}
[/php]

4

Thank you so much for the reply!

I put the code in notepad++, added the php tags, saved it as php document, and uploaded it to a server but it wouldn’t display anything.

Did I do something wrong?

Thank you again. I was about to think no one would help me. :frowning:

5

No problem.

That is just a function you will need to call it to get an output.

Simply put this, for example, inbetween the body tags somewhere:
[php]echo circle_area(6,“diameter”);
[/php]

Or of course you can pass it into a variable and apply any rounding/trimming/validation you want.

6

It’s still all just Greek to me. I think I’m sort of getting a grip on it and then I find out I’m not.

I’m going to paste the code again because, apparently, I’ve put something somewhere it doesn’t belong. Still won’t display in the browser. :frowning:

I checked the syntax in Putty and it had some issues but I couldn’t find them.

Thank you for your help again. I really, really appreciate it so much.

<?php
// variables
$diameter = 6;
$pi = 3.14;
$area = ($diameter * $pi);
$title = "Circle";
        function circle_area($num,$type="radius")
{	
if(is_numeric($num) && is_string($type) && !empty($num) && !empty($type))	
{		
$radius = ($type == "diameter") ? $num/2 : $num; // Radius is set to half the given number if the type is diameter, or unchanged if radius		
$area = pi()*pow($radius,2); // Pi as defined by php multiplied by radius to the power of 2 (squared)		
return $area; // Return result	
}	
else	
{		return -1; // Return Pi when invalid/empty values are given	}
}
        
        echo "<html>	
        <head>
        <title>			
            $title			
         </title>		
        </head>	
         <body>   
            <h1>Area of a Circle</h1>\n";      

         echo circle_area(6,"diameter");      
         echo    "</body>
</html>";
?>
7

Hi,

You need to include another curly brace after the else. That should fix the problem.

8

Didn’t work. :frowning:

Thanks for trying.

9

This task is solved! Thanks for all your help!!