Hello i have problem with isset id like someone to help me fixin this problem. Its this problem Notice: Undefined variable: v in C:\xampp\htdocs\something\something2.php on line 17 and my code is :
<form id="priklad" method="post">
<label>Obvod kruhu:</label>
<?php IF (isset($_POST['v'])) {
$_POST['v'];
}
?>
<label>r:</label><input type="text" name="r"/>
<input type="submit" value="Vypočti"/></br>
<label><?php echo 2*$v;?> cm</label>
</form>
EDIT:
<form id="priklad" method="post">
<label>Obvod kruhu:</label>
<?php If (is_numeric($_POST['v'])) {
$v = $_POST['v'];
}
?>
<label>v:</label><input type="text" name="v"/>
<input type="submit" value="Vypočti"/></br>
<label><?php echo 2*$v;?> cm</label>
</form>
and im getting these errors Notice: Undefined index: v in C:\xampp\htdocs\something\something2.php on line 11 and Notice: Undefined variable: v in C:\xampp\htdocs\something\something2.php on line 17