Parsing and exception contracts

The idea

Parsing answers whether text follows a syntax; validation answers whether its value satisfies your application’s rules. JSON can validly contain null, a scalar, or an object with missing fields. Decoding successfully therefore does not establish that a requested field exists or has the right type. Validate the resulting shape before using it, and distinguish an absent field from a field explicitly containing null.

JSON_THROW_ON_ERROR makes malformed JSON raise JsonException instead of relying on a separate error inspection path. Catch that exception where the application can report or recover from invalid input. Avoid swallowing every Throwable around unrelated business logic. A finally block can perform required cleanup regardless of success, but it should not return a replacement value that hides the original result or failure.

<?php
try {
    $data = json_decode("{bad}", true, 512, JSON_THROW_ON_ERROR);
} catch (JsonException $error) {
    echo "Invalid JSON
";
}

Invalid JSON

The malformed text triggers JsonException because the flag requests throwing behavior. Schema validation would still be needed for syntactically valid input.