What is the purpose of using isset() in PHP and how can it be utilized effectively in handling variables?

The purpose of using isset() in PHP is to determine if a variable is set and is not null. This is useful for checking if a variable exists before using it to avoid potential errors or warnings in the code. isset() can be utilized effectively in handling variables by using it in conditional statements to ensure that a variable is set before using it.

// Check if the variable is set before using it
if(isset($variable)){
    // Use the variable here
    echo $variable;
} else {
    // Handle the case where the variable is not set
    echo "Variable is not set";
}