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# nlohmann::json_sax::binary

    virtual bool binary(binary_t& val) = 0;

A binary value was read.

## Parameters

`val` (in)
  binary value

## Return value

Whether parsing should proceed.

## Notes

It is safe to move the passed binary value.

## Examples

Example

.The example below shows how the SAX interface is used.

    #include <iostream>
    #include <iomanip>
    #include <sstream>
    #include <nlohmann/json.hpp>

    using json = nlohmann::json;

    // a simple event consumer that collects string representations of the passed
    // values; note inheriting from json::json_sax_t is not required, but can
    // help not to forget a required function
    class sax_event_consumer : public json::json_sax_t
    {
      public:
        std::vector<std::string> events;

        bool null() override
        {
            events.push_back("null()");
            return true;
        }

        bool boolean(bool val) override
        {
            events.push_back("boolean(val=" + std::string(val ? "true" : "false") + ")");
            return true;
        }

        bool number_integer(number_integer_t val) override
        {
            events.push_back("number_integer(val=" + std::to_string(val) + ")");
            return true;
        }

        bool number_unsigned(number_unsigned_t val) override
        {
            events.push_back("number_unsigned(val=" + std::to_string(val) + ")");
            return true;
        }

        bool number_float(number_float_t val, const string_t& s) override
        {
            events.push_back("number_float(val=" + std::to_string(val) + ", s=" + s + ")");
            return true;
        }

        bool string(string_t& val) override
        {
            events.push_back("string(val=" + val + ")");
            return true;
        }

        bool start_object(std::size_t elements) override
        {
            events.push_back("start_object(elements=" + std::to_string(elements) + ")");
            return true;
        }

        bool end_object() override
        {
            events.push_back("end_object()");
            return true;
        }

        bool start_array(std::size_t elements) override
        {
            events.push_back("start_array(elements=" + std::to_string(elements) + ")");
            return true;
        }

        bool end_array() override
        {
            events.push_back("end_array()");
            return true;
        }

        bool key(string_t& val) override
        {
            events.push_back("key(val=" + val + ")");
            return true;
        }

        bool binary(json::binary_t& val) override
        {
            events.push_back("binary(val=[...])");
            return true;
        }

        bool parse_error(std::size_t position, const std::string& last_token, const json::exception& ex) override
        {
            events.push_back("parse_error(position=" + std::to_string(position) + ", last_token=" + last_token + ",\n            ex=" + std::string(ex.what()) + ")");
            return false;
        }
    };

    int main()
    {
        // CBOR byte string
        std::vector<std::uint8_t> vec = {{0x44, 0xcA, 0xfe, 0xba, 0xbe}};

        // create a SAX event consumer object
        sax_event_consumer sec;

        // parse CBOR
        bool result = json::sax_parse(vec, &sec, json::input_format_t::cbor);

        // output the recorded events
        for (auto& event : sec.events)
        {
            std::cout << event << "\n";
        }

        // output the result of sax_parse
        std::cout << "\nresult: " << std::boolalpha << result << std::endl;
    }

Output:

    binary(val=[...])

    result: true

## Version history

- Added in version 3.8.0.

Last update: May 17, 2022
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