Are there any best practices for initializing variables in PHP to avoid "Notice: Undefined variable" messages?

When initializing variables in PHP, it's a good practice to assign them a default value to avoid "Notice: Undefined variable" messages. This can be done by using the isset() function to check if the variable is set before using it. By initializing variables with a default value, you can prevent these notices from being displayed.

// Initialize variable with a default value
$variable = isset($variable) ? $variable : 'default_value';