Understanding PHP Functions
<?php
function calculate($num1, $num2, $operation = '+')
{
switch($operation)
{
case '+': // add
return $num1 + $num2;
break;
case '-': // subtract
return $num1 - $num2;
break;
case '*': // multiply
return $num1 * $num2;
break;
case '/': // divide, make sure denominator is not zero
return ($num2 == 0) ? 'Cannot divide by zero' : $num1 / $num2;
break;
default: // Display error message for unknown operation ex 'a', 'b' etc.
return 'Unkown Operation Fool!';
break;
}
}
?>
<html>
<body>
<?php
echo '1 + 3 = ';
echo calculate(1,3);
echo '<br />';
echo '9 x 5 = ';
echo calculate(9,5,'*');
echo '<br />';
echo 'Division by zero test: ';
echo calculate(10, 0, '/');
echo '<br />';
?>
</body>
</html>
