Agghhhh

mensa180

Ok I've just learned some php today. My dad challenged me to make a program that could add numbers and tell you the answers and things by the end of the night and he would give me 5 dollars. I got it done in an hour. So now he's challenging me to make a program that gives you the choice to add or subtract the numbers. No money involved; just a fun challenge. I have what I thought was the right code. but there is something wrong with it and I have been trying to figure it out for hours. Can any of you help?

Here is where the problem lies.

<?php
if ($todo=="A"){

function add($x,$y)
  {
  $total = $x + $y;
  return $total;
  }
  }
print "The answer is " . add($x,$y)
; 
elseif ($todo=="S")


function subtract($x,$y)
  {
  $total = $x - $y;
  return $total;
  }

print "The answer is " . subtract($x,$y) 
?>

Help is appriciated.

thorpe

Use an else, not elseif.

NogDog

Here's a different way to approach it:

if($todo == "S")
{
  $y = $y * -1;  // invert the sign
}
echo "The answer is " . $x + $y;

Gonwee

Heres how i'd do it,

<?php

// X and Y are imported variables, and z is the operator, d division, m multiply, s subtract, a add.

// Set the gets to plain variables
$x = $_GET['x'];
$y = $_GET['y'];
$z = $_GET['z'];

// Switch to do the operation
switch ($z) {
	case 'a':
		$answer = $x+$y;
		$operator = '+';
		break;
	case 's':
		$answer = $x-$y;
		$operator = '-';
		break;
	case 'd':
		$answer = $x/$y;
		$operator = '/';
		break;
	case 'm':
		$answer = $x*$y;
		$operator = '*';
		break;
	default:
		echo "No operator supplied, defaulting to addition...\n";
		$answer = $x+$y;
		break;
}

echo "The solution to the problem, {$x}{$operator}{$y} is, {$answer}";

?>

Problly not living up to the spirit of the challenge, but this is how i'd do it.

Just call the script like this, page.php?x=1&y=1&z=a (that will add 1 and 1)

You could also change the $GET to $POST and use a form to run the script.

mensa180

I do have a form; I probably should have posted it.

Here.

<html>
<body>


<center>

<table border="1" width="750px" bgcolor="CCCC99" >
<tr>
<td>

<center>

<h1>Enter the numbers you would like to be added.</h1>
<br>
<form action="welcome.php" method="
request">

<h2>

First Number: 

</h2>

<br>

<input type="text" name="x" />

<br>

<br>

<br>

<h2>

Second Number:

</h2>

<br>

<input type="text" name="y" /> 

<br>

<h2> Please type A to add.</h2>

<input type="text" name="todo" />

<br>

<input type="submit" />


</form>

</body>
</html>

Gonwee

<?php

if (isset($_POST['submit'])) {

// Set post variables to regular variables
$x = $_POST['x'];
$y = $_POST['y'];
$z = $_POST['z'];

// Switch to do the operation
switch ($z) {
	case 'a':
		$answer = $x+$y;
		$operator = '+';
		break;
	case 's':
		$answer = $x-$y;
		$operator = '-';
		break;
	case 'd':
		$answer = $x/$y;
		$operator = '/';
		break;
	case 'm':
		$answer = $x*$y;
		$operator = '*';
		break;
	default:
		echo "No operator supplied, defaulting to addition...\n";
		$answer = $x+$y;
		break;
}

echo "The solution to the problem, {$x}{$operator}{$y} is, {$answer}";
}

?><html>
	<head>
		<title>Calculate</title>
	</head>

<body>
	<form action="math.php" method="POST">
		<br />
		<table>
			<tr>
				<td><input type="text" size="4" maxlength="30" name="x" /></td>
				<td><select name="z">
					<option value="a">+</option>
					<option value="s">-</option>
					<option value="m">*</option>
					<option value="d">/</option>
				</select></td>
				<td><input type="text" size="4" maxlength="30" name="y" /></td>
			</tr>
			<tr>
				<td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
			</tr>
		</table>
	</form>
</body>
</html>

Might be cheating, but thats a whole script outputs a form, then once submitted gives the results, and put the form back so you can do another problem. And the script should be named math.php to work right, or you'll need to change the action of the form.