Perplexity Pro 2

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Ask 1

仕事でjsonを使いたい場面が発生。


make a program to parse json file by C++

(no file)

#include <iostream>
#include <fstream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main() {
    // Open the JSON file
    std::ifstream file("example.json");

    if (!file.is_open()) {
        std::cerr << "Error opening file" << std::endl;
        return 1;
    }

    // Parse the JSON
    json data;
    try {
        file >> data;
    } catch (json::parse_error& e) {
        std::cerr << "JSON parse error: " << e.what() << std::endl;
        return 1;
    }

    // Access and print some data
    std::cout << "Name: " << data["name"] << std::endl;
    std::cout << "Age: " << data["age"] << std::endl;

    // Access array elements
    std::cout << "Hobbies:" << std::endl;
    for (const auto& hobby : data["hobbies"]) {
        std::cout << "- " << hobby << std::endl;
    }

    return 0;
}

参考。

nlohmann/json

Ask 2

同じtagを含んでいる場合に対応したい。


make a program parse json file include same tag by C++

(no file)

#include <iostream>
#include <fstream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

void printPerson(const json& person) {
    std::cout << "Name: " << person["name"] << std::endl;
    std::cout << "Age: " << person["age"] << std::endl;
    std::cout << "City: " << person["city"] << std::endl;

    std::cout << "Hobbies:" << std::endl;
    for (const auto& hobby : person["hobbies"]) {
        std::cout << "  - " << hobby << std::endl;
    }
    std::cout << std::endl;
}

int main() {
    // Open the JSON file
    std::ifstream file("people.json");

    if (!file.is_open()) {
        std::cerr << "Error opening file" << std::endl;
        return 1;
    }

    // Parse the JSON
    json data;
    try {
        file >> data;
    } catch (json::parse_error& e) {
        std::cerr << "JSON parse error: " << e.what() << std::endl;
        return 1;
    }

    // Access and print data for each person
    for (const auto& person : data["people"]) {
        printPerson(person);
    }

    // Access and print summary data
    std::cout << "Total people: " << data["summary"]["total_people"] << std::endl;
    std::cout << "Average age: " << data["summary"]["average_age"] << std::endl;

    return 0;
}

jsonのsampleも出力してくれる。

(no file)

{
    "people": [
        {
            "name": "John Doe",
            "age": 30,
            "city": "New York",
            "hobbies": ["reading", "swimming"]
        },
        {
            "name": "Jane Smith",
            "age": 25,
            "city": "Los Angeles",
            "hobbies": ["painting", "yoga"]
        },
        {
            "name": "Bob Johnson",
            "age": 35,
            "city": "Chicago",
            "hobbies": ["coding", "gaming"]
        }
    ],
    "summary": {
        "total_people": 3,
        "average_age": 30
    }
}

Ask 3

int型の値を取得したい。


make a program parse json file include same tag by C++, and get a integer value

(no file)

#include <iostream>
#include <fstream>
#include <vector>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main() {
    // Open the JSON file
    std::ifstream file("data.json");

    if (!file.is_open()) {
        std::cerr << "Error opening file" << std::endl;
        return 1;
    }

    // Parse the JSON
    json data;
    try {
        file >> data;
    } catch (json::parse_error& e) {
        std::cerr << "JSON parse error: " << e.what() << std::endl;
        return 1;
    }

    // Vector to store the extracted integer values
    std::vector<int> values;

    // Extract integer values from the "items" array
    for (const auto& item : data["items"]) {
        if (item.contains("value") && item["value"].is_number_integer()) {
            values.push_back(item["value"].get<int>());
        }
    }

    // Print the extracted values
    std::cout << "Extracted integer values:" << std::endl;
    for (const auto& value : values) {
        std::cout << value << std::endl;
    }

    // Calculate and print the sum of the values
    int sum = 0;
    for (const auto& value : values) {
        sum += value;
    }
    std::cout << "Sum of values: " << sum << std::endl;

    return 0;
}

Ask 4

float型の配列の値を取得したい。


make a program parse json file include same tag by C++, and get array of float values

(no file)

#include <iostream>
#include <fstream>
#include <vector>
#include <iomanip>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main() {
    // Open the JSON file
    std::ifstream file("data.json");

    if (!file.is_open()) {
        std::cerr << "Error opening file" << std::endl;
        return 1;
    }

    // Parse the JSON
    json data;
    try {
        file >> data;
    } catch (json::parse_error& e) {
        std::cerr << "JSON parse error: " << e.what() << std::endl;
        return 1;
    }

    // Vector to store the extracted float arrays
    std::vector<std::vector<float>> allValues;

    // Extract float arrays from the "items" array
    for (const auto& item : data["items"]) {
        if (item.contains("values") && item["values"].is_array()) {
            std::vector<float> floatArray;
            for (const auto& value : item["values"]) {
                if (value.is_number()) {
                    floatArray.push_back(value.get<float>());
                }
            }
            if (!floatArray.empty()) {
                allValues.push_back(floatArray);
            }
        }
    }

    // Print the extracted float arrays
    std::cout << "Extracted float arrays:" << std::endl;
    for (size_t i = 0; i < allValues.size(); ++i) {
        std::cout << "Item " << i + 1 << ": ";
        for (const auto& value : allValues[i]) {
            std::cout << std::fixed << std::setprecision(2) << value << " ";
        }
        std::cout << std::endl;
    }

    // Calculate and print the average of each array
    std::cout << "\nAverages:" << std::endl;
    for (size_t i = 0; i < allValues.size(); ++i) {
        float sum = 0;
        for (const auto& value : allValues[i]) {
            sum += value;
        }
        float average = sum / allValues[i].size();
        std::cout << "Item " << i + 1 << " average: " << std::fixed << std::setprecision(2) << average << std::endl;
    }

    return 0;
}

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