What potential pitfalls should be considered when using isset() in PHP, as demonstrated in the code snippet provided?

When using isset() in PHP, it's important to consider that it only checks if a variable is set and not null. This means that variables set to an empty string, 0, or false will still return true with isset(). To accurately check if a variable is set and not empty, you can combine isset() with empty() or use a strict comparison with null.

// Incorrect usage of isset()
$var = "";
if(isset($var)){
    echo "Variable is set";
} else {
    echo "Variable is not set";
}

// Correct way to check if variable is set and not empty
$var = "";
if(isset($var) && $var !== ""){
    echo "Variable is set and not empty";
} else {
    echo "Variable is not set or empty";
}