How does the isset() function help in preventing undefined variable errors in PHP?

When working with PHP, undefined variable errors can occur when trying to access a variable that has not been set or initialized. This can lead to unexpected behavior in your code and make debugging more difficult. The isset() function in PHP helps prevent these errors by checking if a variable is set and not null before attempting to use it. By using isset() to validate the existence of a variable before accessing it, you can avoid undefined variable errors and ensure that your code runs smoothly.

// 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";
}