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# std::swap<basic_json>

    namespace std {
        void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2);
    }

Exchanges the values of two JSON objects.

## Parameters

`j1` (in, out)
  value to be replaced by `j2`
`j2` (in, out)
  value to be replaced by `j1`

## Possible implementation

    void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2)
    {
        j1.swap(j2);
    }

## Examples

Example

The following code shows how two values are swapped with `std::swap`.

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

    using json = nlohmann::json;

    int main()
    {
        // create JSON values
        json j1 = {{"one", 1}, {"two", 2}};
        json j2 = {1, 2, 4, 8, 16};

        std::cout << "j1 = " << j1 << " | j2 = " << j2 << '\n';

        // swap values
        std::swap(j1, j2);

        std::cout << "j1 = " << j1 << " | j2 = " << j2 << std::endl;
    }

Output:

    j1 = {"one":1,"two":2} | j2 = [1,2,4,8,16]
    j1 = [1,2,4,8,16] | j2 = {"one":1,"two":2}

## See also

- swap

## Version history

- Added in version 1.0.0.
- Extended for arbitrary basic_json types in version 3.10.5.

Last update: May 1, 2022
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