PHP calculator division by zero error ?fix? - php

Question

I Want to make a calculator. I made the code but problem is when some number divide by zero it gives an Exception,so it is unable to generate the correct result, is there a fix for this? see code
<?php
$x = $_POST['x'];
$y = $_POST['y'];
$tafel = 10;
$antwoord = '' ;
{
if($y = 0)
return 'Voer voor y een ander getal in';
}
switch ($_POST['type']) {
case 'plus':
$antwoord = $x + $y;
break;
case 'keer':
$antwoord = $x * $y;
break;
case 'wortel':
$antwoord = sqrt($x);
break;
case 'min':
$antwoord = $x - $y;
break;
case 'deel':
$antwoord = $x / $y;
break;
case 'kwadraat':
$antwoord = pow($x, 2);
break;
case 'macht':
$antwoord = pow($x, $y);
break;
case 'tafel':
for($i = $x; $i <= 10; $i++){
echo $x * $i.'<br>';
}
break;
default:
# code...
break;
}
echo '<h1 id="answer"> Antwoord:</h1><br>';
echo $antwoord;
?>

Answer 1

The following statement will always be true as you're actually assigning the value within your if statement, instead of comparing it.
if($y = 0)
to
if(0 == $y)

Answer 2

Just change this:
(If this code is not in a function)
return 'Voer voor y een ander getal in';
to this:
die('Voer voor y een ander getal in');
So that the script stops! And you have to make a comparison like this:
if($y == 0)
//^^ See here 2x '='
For more information about comparison operator see the manual: http://php.net/manual/en/language.operators.comparison.php

Answer 3

The following code work fine for you
= means assign
== means comparison
in your situation your need is to compare in if condition
<?php
$x = $_POST['x'];
$y = $_POST['y'];
$tafel = 10;
$antwoord = '' ;
{
if($y == 0)
return 'Voer voor y een ander getal in';
}
switch ($_POST['type']) {
case 'plus':
$antwoord = $x + $y;
break;
case 'keer':
$antwoord = $x * $y;
break;
case 'wortel':
$antwoord = sqrt($x);
break;
case 'min':
$antwoord = $x - $y;
break;
case 'deel':
$antwoord = $x / $y;
break;
case 'kwadraat':
$antwoord = pow($x, 2);
break;
case 'macht':
$antwoord = pow($x, $y);
break;
case 'tafel':
for($i = $x; $i <= 10; $i++){
echo $x * $i.'<br>';
}
break;
default:
# code...
break;
}
echo '<h1 id="answer"> Antwoord:</h1><br>';
echo $antwoord;
?>