预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

The following constants indicate the type of error returned by json_last_error(). They are all available as of PHP 5.3.0.

JSON_ERROR_NONE (integer)

No error has occurred.

JSON_ERROR_DEPTH (integer)

The maximum stack depth has been exceeded.

JSON_ERROR_CTRL_CHAR (integer)

Control character error, possibly incorrectly encoded.

JSON_ERROR_SYNTAX (integer)

Syntax error.

JSON_ERROR_UTF8 (integer)

Malformed UTF-8 characters, possibly incorrectly encoded. This constant is available as of PHP 5.3.1.

The following constants can be combined to form options for json_encode(). They are all available as of PHP 5.3.0.

JSON_HEX_TAG (integer)

All < and > are converted to \u003C and \u003E.

JSON_HEX_AMP (integer)

All &s are converted to \u0026.

JSON_HEX_APOS (integer)

All ' are converted to \u0027.

JSON_HEX_QUOT (integer)

All " are converted to \u0022.

JSON_FORCE_OBJECT (integer)

Outputs an object rather than an array when a non-associative array is used. Especially useful when the recipient of the output is expecting an object and the array is empty.