json_encode
Returns a string containing the JSON representation of the supplied value.
The encoding is affected by the supplied flags and additionally the encoding of float values depends on the value of serialize_precision.
Parameters
- value
-
The value being encoded. Can be any type except a resource.
All string data must be UTF-8 encoded.
PHP implements a superset of JSON as specified in the original RFC 7159.
- flags
-
Bitmask consisting of JSON_FORCE_OBJECT, JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_INVALID_UTF8_IGNORE, JSON_INVALID_UTF8_SUBSTITUTE, JSON_NUMERIC_CHECK, JSON_PARTIAL_OUTPUT_ON_ERROR, JSON_PRESERVE_ZERO_FRACTION, JSON_PRETTY_PRINT, JSON_UNESCAPED_LINE_TERMINATORS, JSON_UNESCAPED_SLASHES, JSON_UNESCAPED_UNICODE, JSON_THROW_ON_ERROR. The behaviour of these constants is described on the JSON constants page.
- depth
-
Set the maximum depth. Must be greater than zero.
Return Values
Returns a JSON encoded string on success or false on failure.
Notes
Note:
In the event of a failure to encode, json_last_error can be used to determine the exact nature of the error.
Note:
When encoding an array, if the keys are not a continuous numeric sequence starting from 0, all keys are encoded as strings, and specified explicitly for each key-value pair.
Note:
Like the reference JSON encoder, json_encode will generate JSON that is a simple value (that is, neither an object nor an array) if given a string, int, float or bool as an input value. While most decoders will accept these values as valid JSON, some may not, as the specification is ambiguous on this point.
To summarise, always test that your JSON decoder can handle the output you generate from json_encode.
Changelog
| Version | Description |
| 7.3.0 | JSON_THROW_ON_ERROR flags was added. |
| 7.2.0 | JSON_INVALID_UTF8_IGNORE, and JSON_INVALID_UTF8_SUBSTITUTE flags were added. |
| 7.1.0 | JSON_UNESCAPED_LINE_TERMINATORS flags was added. |
| 7.1.0 | serialize_precision is used instead of precision when encoding double values. |