Why Does My PHP `json_decode()` Return NULL Despite Valid JSON?

PHP json_decode() Decoding Issue with Seemingly Valid JSON

When attempting to decode JSON stored in a plaintext file using the json_decode function in PHP, some users encounter inexplicable NULL returns despite the apparent validity of the JSON structure.

The affected JSON often aligns with JSON schema validation standards and passes rigorous testing on platforms like http://jsonlint.com/. However, when decoding the JSON in PHP, it remains elusive.

To resolve this issue, consider incorporating the following line of code into your decoding process:

json_decode(preg_replace('/[\x00-\x1F\x80-\xFF]/', '', $json_string), true);

This modified json_decode invocation replaces any invisible or non-printable characters in the JSON string (such as control characters, illegal UTF-8 characters, or special characters) with an empty string. These characters can cause discrepancies during decoding and result in NULL returns.

By filtering out such characters, the modified code ensures that the json_decode function can parse the JSON string accurately, enabling it to return a valid PHP representation of the JSON data.

The above is the detailed content of Why Does My PHP `json_decode()` Return NULL Despite Valid JSON?. For more information, please follow other related articles on the PHP Chinese website!