PHP JSON Functions

PHP JSON Introduction

The JSON extension implements the JavaScript Object Notation data-interchange format.

In PHP 5, the decoding is handled by a parser based on the JSON_checker by Douglas Crockford.

PHP 7 has a new and improved parser specifically written for PHP and licensed under the PHP license.

From PHP 5.2.0, the JSON functions are enabled by default. There is no installation needed to use these functions.

Function	Description
json_decode()	Decodes a JSON string
json_encode()	Encode a value to JSON format
json_last_error()	Returns the last error occurred
json_last_error_msg()	Returns the error string of the last json_encode() or json_decode() call

Constant	Type	Description
JSON_ERROR_NONE	Integer	No error has occurred
JSON_ERROR_DEPTH	Integer	Maximum stack depth has been exceeded
JSON_ERROR_STATE_MISMATCH	Integer	Invalid/Malformed JSON
JSON_ERROR_CTRL_CHAR	Integer	Control character error
JSON_ERROR_SYNTAX	Integer	Syntax error
JSON_ERROR_UTF8	Integer	Malformed UTF-8 characters. PHP 5.3
JSON_ERROR_RECURSION	Integer	Invalid recursive reference values. PHP 5.5
JSON_ERROR_INF_OR_NAN	Integer	Invalid NAN or INF values. PHP 5.5
JSON_ERROR_UNSUPPORTED_TYPE	Integer	Invalid type. PHP 5.5
JSON_ERROR_INVALID_PROPERTY_NAME	Integer	Invalid property name. PHP 7.0
JSON_ERROR_UTF16	Integer	Malformed UTF-16 characters. PHP 7.0
JSON_BIGINT_AS_STRING	Integer
JSON_OBJECT_AS_ARRAY	Integer
JSON_HEX_TAG	Integer
JSON_HEX_AMP	Integer
JSON_HEX_APOS	Integer
JSON_HEX_QUOT	Integer
JSON_FORCE_OBJECT	Integer
JSON_NUMERIC_CHECK	Integer
JSON_PRETTY_PRINT	Integer
JSON_UNESCAPED_SLASHES	Integer
JSON_PARTIAL_OUTPUT_ON_ERROR	Integer
JSON_PRESERVE_ZERO_FRACTION	Integer
JSON_UNESCAPED_LINE_TERMINATORS	Integer
JSON_INVALID_UTF8_IGNORE	Integer
JSON_INVALID_UTF8_SUBSTITUTE	Integer
JSON_THROWN_ON_ERROR	Integer