PHP json_encode() Function
Quick summary: The PHP json_encode() function converts a value into a JSON string.
PHP json_encode() Syntax
json_encode(mixed $value, int $flags = 0, int $depth = 512): string|falsePHP
PHP json_encode() Basic examples
var_dump(json_encode(['a'=>1,'b'=>2]));PHP
Output:
string(13) "{"a":1,"b":2}"Encodes an associative array as JSON.
PHP json_encode() Real-world usage
$data = ['status'=>'ok'];
echo json_encode($data);PHP
Output:
{"status":"ok"}Creates JSON API responses.
PHP json_encode() Edge cases
var_dump(json_encode(INF));PHP
Output:
bool(false)INF and NAN cannot be encoded by default.
PHP json_encode() Common mistakes
Ignoring encoding errors
json_encode can fail silently.
Incorrect
json_encode($data);Correct
json_encode($data, JSON_THROW_ON_ERROR);Enable exceptions for safer encoding.
PHP json_encode() Frequently Asked Questions
What does json_encode() do in PHP?
Converts a PHP value into a JSON string.
Why does json_encode() return false?
Encoding error, check json_last_error().
How to handle errors in json_encode()?
Use JSON_THROW_ON_ERROR flag.
Does json_encode() support UTF-8?
Yes, input must be UTF-8.
Use case?
APIs and data serialization.
Difference from serialize()?
JSON is language-independent.
Common mistake?
Passing invalid UTF-8.
Can encode objects?
Yes.
Performance?
Fast.
Can pretty print JSON?
Yes with JSON_PRETTY_PRINT.
Safe?
Yes.
Best practice?
Use flags for strict handling.