Calculator PHP SCRIPTS

**bullet4747** Sat Nov 03, 2012 4:54 pm

<?php

?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<title>Calculator</title>

</head>

<body>

<?php

// basic calculator program

function showForm() {

?>

All field are required, however, if you forget any, we will put a random number in for you. <br />

<table border="0">

<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post">

<tr>

<td>Number:</td>

<td><input type="text" maxlength="3" name="number" size="4" /></td>

</tr>

<span id="square">

<tr>

<td>Another number:</td>

<td><input type="text" maxlength="4" name="number2" size="4" /></td>

</tr>

</span>

<tr>

<td valign="top">Operator:</td>

<td><input type="radio" name="opt" value="+" </>+<br />

<input type="radio" name="opt" value="-" />-<br />

<input type="radio" name="opt" value="*" />*<br />

<input type="radio" name="opt" value="/" />/<br />

<input type="radio" name="opt" value="^2" />x<sup>2</sup><br />

<input type="radio" name="opt" value="sqrt" />sqrt<br />

<input type="radio" name="opt" value="^" />^<br />

</td>

</tr>

<tr>

<td>Rounding:</td>

<td><input type="text" name="rounding" value="4" size="4" maxlength="4" /></td>

<td><small>(Enter how many digits you would like to round to)</small>

</td>

</tr>

<tr>

<td><input type="submit" value="Calculate" name="submit" /></td>

</tr>

</form>

</table>

<?php

}

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

showForm();

} else {

$errors = array();

$error = false;

if (!is_numeric($_POST['number'])) {

(int)$_POST['number'] = rand(1,200);

}

if (empty($_POST['number'])) {

(int)$_POST['number'] = rand(1,200);

}

if (!is_numeric($_POST['number2'])) {

(int)$_POST['number2'] = rand(1,200);

}

if (empty($_POST['number2'])) {

(int)$_POST['number2'] = rand(1,200);

}

if (empty($_POST['rounding'])) {

$round = 0;

}

if (!isset($_POST['opt'])) {

$errors[] = "You must select an operation.";

$error = true;

}

if (strpbrk($_POST['number'],"-") and strpbrk($_POST['number2'],"0.") and $_POST['opt'] == "^") {

$errors[] = "You cannot raise a negative number to a decimal, this is impossible. <a href=\"http://hudzilla.org/phpwiki/index.php?title=Other_mathematical_conversion_functions\">Why?</a>";

$error = true;

}

if ($error != false) {

echo "We found these errors:";

echo "<ul>";

foreach ($errors as $e) {

echo "<li>$e</li>";

}

echo "</ul>";

} else {

switch ($_POST['opt']) {

case "+":

$result = (int)strip_tags($_POST['number']) + (int)strip_tags($_POST['number2']);

echo "The answer to " . (int)strip_tags($_POST['number']) . " $_POST[opt] " . (int)strip_tags($_POST['number2']) . " is $result.";

break;

case "-";

$result = (int)strip_tags($_POST['number']) - (int)strip_tags($_POST['number2']);

echo "The answer to " . (int)strip_tags($_POST['number']) . " $_POST[opt] " . (int)strip_tags($_POST['number2']) . " is $result.";

break;

case "*";

$result = (int)strip_tags($_POST['number']) * (int)strip_tags($_POST['number2']);

echo "The answer to " . (int)strip_tags($_POST['number']) . " $_POST[opt] " . (int)$_POST['number2'] . " is $result.";

break;

case "/";

$result = (int)strip_tags($_POST['number']) / (int)strip_tags($_POST['number2']);

$a = ceil($result);

echo "<br />";

echo "<hr />";

echo "<h2>Rounding</h2>";

echo "$result rounded up is $a";

echo "<br />";

$b = floor($result);

echo "$result rounded down is $b";

echo "<br />";

$h = round($result,(int)$_POST['rounding']);

echo "$result rounded to $_POST[rounding] digits is " . $h;

break;

case "^2":

$result = (int)strip_tags($_POST['number']) * (int)strip_tags($_POST['number2']);

$a = (int)$_POST['number2'] * (int)$_POST['number2'];

echo "The answer to " . (int)$_POST['number'] . "<sup>2</sup> is " . $result;

echo "<br />";

echo "The answer to " . (int)$_POST['number2'] . "<sup>2</sup> is " . $a;

break;

case "sqrt":

$result = (int)strip_tags(sqrt($_POST['number']));

$sqrt2 = (int)strip_tags(sqrt($_POST['number2']));

echo "The square root of " . (int)strip_tags($_POST['number']) . " is " . $result;

echo "<br />";

echo "The square root of " . (int)strip_tags($_POST['number2']) . " is " . $sqrt2;

echo "<br />";

echo "The square root of " . (int)strip_tags($_POST['number']) . " rounded to " . strip_tags($_POST[rounding]) . " digits is " . round($result,(int)$_POST['rounding']);

echo "<br />";

echo "The square root of " . (int)strip_tags($_POST['number2']) . " rounded to " . strip_tags($_POST[rounding]) . " digits is " . round($sqrt2,(int)strip_tags($_POST['rounding']));

break;

case "^":

$result = (int)strip_tags(pow($_POST['number'],$_POST['number2']));

$pow2 = (int)strip_tags(pow($_POST['number2'],$_POST['number']));

echo (int)$_POST['number'] . "<sup>" . strip_tags($_POST[number2]) . "</sup> is " . $result;

echo "<br />";

echo (int)$_POST['number2'] . "<sup>" . strip_tags($_POST[number]) . "</sup> is " . $pow2;

break;

}

}

}

echo "<br />";

?>

<a href="calc.php">Go Back</a>

</body>

</html>