JSON for Modern C++  3.7.2

◆ parse_error

template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
using nlohmann::basic_json::parse_error = detail::parse_error

This exception is thrown by the library when a parse error occurs. Parse errors can occur during the deserialization of JSON text, CBOR, MessagePack, as well as when using JSON Patch.

Member byte holds the byte index of the last read character in the input file.

Exceptions have ids 1xx.

name / id example message description
json.exception.parse_error.101 parse error at 2: unexpected end of input; expected string literal This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member byte indicates the error position.
json.exception.parse_error.102 parse error at 14: missing or wrong low surrogate JSON uses the \uxxxx format to describe Unicode characters. Code points above above 0xFFFF are split into two \uxxxx entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point.
json.exception.parse_error.103 parse error: code points above 0x10FFFF are invalid Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid.
json.exception.parse_error.104 parse error: JSON patch must be an array of objects RFC 6902 requires a JSON Patch document to be a JSON document that represents an array of objects.
json.exception.parse_error.105 parse error: operation must have string member 'op' An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors.
json.exception.parse_error.106 parse error: array index '01' must not begin with '0' An array index in a JSON Pointer (RFC 6901) may be 0 or any number without a leading 0.
json.exception.parse_error.107 parse error: JSON pointer must be empty or begin with '/' - was: 'foo' A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a / character.
json.exception.parse_error.108 parse error: escape character '~' must be followed with '0' or '1' In a JSON Pointer, only ~0 and ~1 are valid escape sequences.
json.exception.parse_error.109 parse error: array index 'one' is not a number A JSON Pointer array index must be a number.
json.exception.parse_error.110 parse error at 1: cannot read 2 bytes from vector When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read.
json.exception.parse_error.112 parse error at 1: error reading CBOR; last byte: 0xF8 Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read.
json.exception.parse_error.113 parse error at 2: expected a CBOR string; last byte: 0x98 While parsing a map key, a value that is not a string has been read.
json.exception.parse_error.114 parse error: Unsupported BSON record type 0x0F The parsing of the corresponding BSON record type is not implemented (yet).
Note
For an input with n bytes, 1 is the index of the first character and n+1 is the index of the terminating null byte or the end of file. This also holds true when reading a byte vector (CBOR or MessagePack).
Example
The following code shows how a parse_error exception can be caught.
1 #include <iostream>
2 #include <nlohmann/json.hpp>
3 
4 using json = nlohmann::json;
5 
6 int main()
7 {
8  try
9  {
10  // parsing input with a syntax error
11  json::parse("[1,2,3,]");
12  }
13  catch (json::parse_error& e)
14  {
15  // output exception information
16  std::cout << "message: " << e.what() << '\n'
17  << "exception id: " << e.id << '\n'
18  << "byte position of error: " << e.byte << std::endl;
19  }
20 }

Output (play with this example online):
message: [json.exception.parse_error.101] parse error at line 1, column 8: syntax error while parsing value - unexpected ']'; expected '[', '{', or a literal
exception id: 101
byte position of error: 8
The example code above can be translated with
g++ -std=c++11 -Isingle_include doc/examples/parse_error.cpp -o parse_error 
See also
- exception for the base class of the library exceptions
- invalid_iterator for exceptions indicating errors with iterators
- type_error for exceptions indicating executing a member function with a wrong type
- out_of_range for exceptions indicating access out of the defined range
- other_error for exceptions indicating other library errors
Since
version 3.0.0

Definition at line 14776 of file json.hpp.

nlohmann::basic_json::parse_error
detail::parse_error parse_error
exception indicating a parse error
Definition: json.hpp:14776
nlohmann::basic_json::parse
static basic_json parse(detail::input_adapter &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true)
deserialize from a compatible input
Definition: json.hpp:20757
nlohmann::json
basic_json<> json
default JSON class
Definition: json.hpp:2445