It’s very easy like this :
$var = 'Hello my name is Alex?';
if (strpos($var, 'name') !== false) {
echo 'true';
}Using PDO (for any supported database driver):
$stmt = $pdo->prepare('SELECT * FROM users WHERE name = :name');
$stmt->execute(array('name' => $name));
foreach ($stmt as $row) {
// Do something with $row
}2. Using MySQLi (for MySQL):
$stmt = $dbConnection->prepare('SELECT * FROM employees WHERE name = ?');
$stmt->bind_param('s', $name); // 's' specifies the variable type => 'string'
$stmt->execute();
$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
// Do something with $row
}Q1: this notice means $varname is not defined at current scope of the script.
Q2: Use of isset(), empty() conditions before using any suspicious variable works well.
Solution
// recommended solution for recent PHP versions
$user_name = $_SESSION['user_name'] ?? '';
// pre-7 PHP versions
$user_name = '';
if (!empty($_SESSION['user_name'])) {
$user_name = $_SESSION['user_name'];
}Anoter solution :
// not the best solution, but works
// in your php setting use, it helps hiding site wide notices
error_reporting(E_ALL ^ E_NOTICE);