In the provided PHP code, what specific changes need to be made to ensure compatibility with PHP 7.1?

The specific changes needed to ensure compatibility with PHP 7.1 involve updating the code to use the null coalescing operator (??) instead of the deprecated "or" operator for assigning default values to variables. This change will prevent any potential errors or warnings that may arise in PHP 7.1 due to the use of the deprecated operator.

// Before
$variable = $value or 'default';

// After
$variable = $value ?? 'default';