How can you handle undefined variables in PHP to prevent errors?

When dealing with undefined variables in PHP, you can use the isset() function to check if a variable is set before trying to use it. This helps prevent errors that may occur when trying to access a variable that has not been defined. By checking if the variable is set, you can avoid issues such as "Undefined variable" notices and ensure 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 when the variable is undefined
    echo "Variable is not defined";
}