What are the potential pitfalls of using isset() and empty() functions in PHP conditional statements?

The potential pitfalls of using isset() and empty() functions in PHP conditional statements is that they can produce unexpected results when dealing with variables that are set to empty strings, null values, or arrays with empty values. To avoid these pitfalls, it's recommended to explicitly check for null values or empty strings using strict comparison operators (=== and !==) instead of relying solely on isset() and empty() functions.

// Example of using strict comparison operators to avoid pitfalls with isset() and empty()

// Variable declaration
$var = '';

// Check if variable is set and not empty
if(isset($var) && $var !== '') {
    // Variable is set and not empty
    echo 'Variable is set and not empty';
} else {
    // Variable is either not set or empty
    echo 'Variable is either not set or empty';
}