json_validate

(PHP 8 >= 8.3.0)

json_validateChecks if a string contains valid JSON

Description

json_validate(string $json, int $depth = 512, int $flags = 0): bool

Returns whether the given string is syntactically valid JSON. If json_validate() returns true, json_decode() will successfully decode the given string when using the same depth and flags.

If json_validate() returns false, the cause can be retrieved using json_last_error() and json_last_error_msg().

json_validate() uses less memory than json_decode() if the decoded JSON payload is not used, because it does not need to build the array or object structure containing the payload.

Caution

Calling json_validate() immediately before json_decode() will unnecessarily parse the string twice, as json_decode() implicitly performs validation during decoding.

json_validate() should therefore only be used if the decode JSON payload is not immediately used and knowing whether the string contains valid JSON is needed.

Parameters

json

The string to validate.

This function only works with UTF-8 encoded strings.

Note:

PHP implements a superset of JSON as specified in the original » RFC 7159.

depth

Maximum nesting depth of the structure being decoded. The value must be greater than 0, and less than or equal to 2147483647.

flags

Currently only JSON_INVALID_UTF8_IGNORE is accepted.

Return Values

Returns true if the given string is syntactically valid JSON, otherwise returns false.

Errors/Exceptions

If depth is outside the allowed range, a ValueError is thrown.

Examples

Example #1 json_validate() examples

<?php
var_dump
(json_validate('{ "test": { "foo": "bar" } }'));
var_dump(json_validate('{ "": "": "" } }'));
?>

The above example will output:

bool(true)
bool(false)

See Also

add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top