I have this code at the moment only the addition is working subtraction is giving me the correct answer but a negative one. Please help See my code below
<!DOCTYPE html>
<html>
<head>
<title>Calculator</title>
</head>
<body>
<style>
.calculator-body {
background-color: #CCCCCC;
max-width: 300px;
margin: 0 auto;
}
form {
margin: 0 auto;
max-width: 960px;
text-align: center;
}
#screen {
padding: 5px;
font-size: 22px;
position: relative;
}
</style>
<?php
$number = $_POST['number'];
$op = $_POST['op'];
$ops = $_POST['ops'];
$store = $_POST['store'];
$screen = $_POST['screen'];
$ans = $_POST['equal'];
if (isset($_POST['screen'])) {
$screen = $number;
$screen = $ans;
}
if (isset($_POST['op'])) {
$ops = $op;
$screen .= $ops;
$ans += $number;
}
if (isset($_POST['number'])) {
$screen = $number;
$number = $screen;
// $number .= $tore;
}
// $screen .= $ans;
if (isset($_POST['equal'])) {
$ans = $number + $op + $ans;
// if(isset($_POST['equal']))
// {
switch ($op) {
case '-':
$ans = $number - $ans;
// $screen = $ans;
break;
case '+':
$ans = $number + $ans;
// $screen = $ans;
break;
case '*':
$ans = $number * $ans;
break;
}
}
?>
<form action="" method="post">
<div class="calculator-body calculator">
<div class="screen-wrapper">
<input type="text" id="screen" name="screen" value="<?php echo $screen; ?>">
</div>
<div class="column">
<input type="reset" value="c" name="op" id="clear">
<input type="submit" value="del" name="op" id="backspace"/>
</div>
<div class="column">
<input type="submit" value="7" name="number"/>
<input type="submit" value="8" name="number"/>
<input type="submit" value="9" name="number"/>
<input type="submit" value="/" name="op" id="divide"/>
</div>
<div class="column">
<input type="submit" value="4" name="number"/>
<input type="submit" value="5" name="number"/>
<input type="submit" value="6" name="number"/>
<input type="submit" value="*" name="op" id="multiply"/>
</div>
<div class="column">
<input type="submit" value="1" name="number"/>
<input type="submit" value="2" name="number"/>
<input type="submit" value="3" name="number"/>
<input type="submit" value="-" name="op" id="subtract"/>
</div>
<div class="column">
<input type="submit" value="0" name="number"/>
<input type="submit" value="." name="number" id="dot"/>
<input type="submit" value="=" name="equal" id="equal"/>
<input type="submit" name="op" value="+" id="plus"/>
</div>
<input type="text" value="<?php echo $ops; ?>" name="ops"/>
<input type="text" value="<?php echo $ans; ?>" name="store"/>
<input type="text" value="<?php echo $ans; ?>" name="equal"/>
</form>
</body>
</html>