以下是一个简单的C++ JSON解析器的示例代码：

#include 
#include 
#include 

enum class JSONValueType {
    OBJECT,
    ARRAY,
    STRING,
    NUMBER,
    BOOL,
    NULL_VALUE
};

struct JSONValue {
    JSONValueType type;
    std::string key;
    std::string value;
    std::vector children;
};

class JSONParser {
public:
    JSONValue parse(const std::string& json) {
        index = 0;
        return parseValue(json);
    }

private:
    JSONValue parseValue(const std::string& json) {
        skipWhitespace(json);
        char currentChar = json[index];

        if (currentChar == '{') {
            return parseObject(json);
        } else if (currentChar == '[') {
            return parseArray(json);
        } else if (currentChar == '"') {
            return parseString(json);
        } else if (currentChar == 't' || currentChar == 'f') {
            return parseBool(json);
        } else if (currentChar == 'n') {
            return parseNull(json);
        } else {
            return parseNumber(json);
        }
    }

    JSONValue parseObject(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::OBJECT;

        index++;  // Skip '{'

        while (json[index] != '}') {
            JSONValue child = parseValue(json);
            value.children.push_back(child);

            if (json[index] == ',') {
                index++;  // Skip ','
            }
        }

        index++;  // Skip '}'

        return value;
    }

    JSONValue parseArray(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::ARRAY;

        index++;  // Skip '['

        while (json[index] != ']') {
            JSONValue child = parseValue(json);
            value.children.push_back(child);

            if (json[index] == ',') {
                index++;  // Skip ','
            }
        }

        index++;  // Skip ']'

        return value;
    }

    JSONValue parseString(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::STRING;

        index++;  // Skip '"'

        std::string stringValue;

        while (json[index] != '"') {
            stringValue += json[index++];
        }

        index++;  // Skip '"'

        value.value = stringValue;

        return value;
    }

    JSONValue parseBool(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::BOOL;

        if (json[index] == 't') {
            value.value = "true";
            index += 4;  // Skip "true"
        } else {
            value.value = "false";
            index += 5;  // Skip "false"
        }

        return value;
    }

    JSONValue parseNull(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::NULL_VALUE;

        value.value = "null";
        index += 4;  // Skip "null"

        return value;
    }

    JSONValue parseNumber(const std::string& json) {
        JSONValue value;
        value.type = JSONValueType::NUMBER;

        std::string numberString;

        while (isdigit(json[index]) || json[index] == '.') {
            numberString += json[index++];
        }

        value.value = numberString;

        return value;
    }

    void skipWhitespace(const std::string& json) {
        while (isspace(json[index])) {
            index++;
        }
    }

    int index;
};

int main() {
    std::string json = R"({"name": "John", "age": 30, "isStudent": true, "grades": [90, 85, 95]})";

    JSONParser parser;
    JSONValue value = parser.parse(json);

    std::cout << "Parsed JSON:" << std::endl;
    std::cout << "Type: " << static_cast(value.type) << std::endl;
    std::cout << "Key: " << value.key << std::endl;
    std::cout << "Value: " << value.value << std::endl;

    std::cout << "Children:" << std::endl;
    for (const JSONValue& child : value.children) {
        std::cout << "Type: " << static_cast(child.type) << std::endl;
        std::cout << "Key: " << child.key << std::endl;
        std::cout << "Value: " << child.value << std::endl;
    }

    return 0;
}

该示例代码实现了一个简