Member Avatar for luweegee 
<?php
session_start();

$con = mysql_connect("localhost","root","");
$sql = mysql_select_db("blog", $con) or die(mysql_error());

?>

<html>
	<head>
		<title>///</title>
	</head>
		<body>
			<div id="admin-content">
			<?php
			
			if($_SESSION['uid']){
				$sel = "SELECT * FROM `users` WHERE `id`='".$_SESSION['uid']."' ";
				$result = mysql_query($sql) or die (mysql_error());
		
			if(mysql_num_rows($res) == 0){
				session_destroy();
			echo "Please <a href='login.php'>Login</a> to your account, or <a href='register.php'>Register</a> new account!";
				}else{
				$row = mysql_fetch_assoc($res);
				echo "Welcome back, <a href='index.php?act=profile&id=".$row['id']."'>".$row['username']."</a>! <a href='logout.php' onClick='return confirmLogout()'>logout</a>";
				if($row['admin'] == '1'){
								echo "admin Section";
							}
				
					}
					} else {
					echo "Please <a href='login.php'>Login</a> to your account, or <a href='register.php'>Register</a> new account!";
					}
					
			?>
		</div>
		</body>
</html>

I got error on line 17, which is "Undefined Index: uid". I'm a new in php please help me guys

  • 2 Contributors
  • 4 Replies
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  • 6 Hours Discussion Span
  • Latest Post Latest Post by luweegee
Member Avatar for cwarn23

Try replacing line 17 with the following if statement:

if(isset($_SESSION['uid']) && $_SESSION['uid']){
Member Avatar for luweegee

thanks sir it works...but why? can you explain sir?

Member Avatar for cwarn23

thanks sir it works...but why? can you explain sir?

Well basically when checking for the value of a variable (in this case checking in the if statement) you first must check if it's defined unless you know it's defined. So in this instance the variable $_SESSION was never given a value so it triggered an error. However when the if (isset($_SESSION) was put before it, php check if the variable had a value then php found out that no it didn't so false the if statment and didn't pass on any error messages.

Member Avatar for luweegee

thanks sir for helping me. I must defined 1st my variable before the declaration of $_SESSION...

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