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# nlohmann::basic_json::operator!=

    bool operator!=(const_reference lhs, const_reference rhs) noexcept;

    template<typename ScalarType>
    bool operator!=(const_reference lhs, const ScalarType rhs) noexcept;

    template<typename ScalarType>
    bool operator!=(ScalarType lhs, const const_reference rhs) noexcept;

Compares two JSON values for inequality by calculating `!(lhs == rhs)`.

## Template parameters

`ScalarType`
  a scalar type according to `std::is_scalar<ScalarType>::value`

## Parameters

`lhs` (in)
  first value to consider
`rhs` (in)
  second value to consider

## Return value

whether the values `lhs` and `rhs` are not equal

## Exception safety

No-throw guarantee: this function never throws exceptions.

## Complexity

Linear.

## Examples

Example

The example demonstrates comparing several JSON types.

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

    using json = nlohmann::json;

    int main()
    {
        // create several JSON values
        json array_1 = {1, 2, 3};
        json array_2 = {1, 2, 4};
        json object_1 = {{"A", "a"}, {"B", "b"}};
        json object_2 = {{"B", "b"}, {"A", "a"}};
        json number_1 = 17;
        json number_2 = 17.000000000000001L;
        json string_1 = "foo";
        json string_2 = "bar";

        // output values and comparisons
        std::cout << std::boolalpha;
        std::cout << array_1 << " != " << array_2 << " " << (array_1 != array_2) << '\n';
        std::cout << object_1 << " != " << object_2 << " " << (object_1 != object_2) << '\n';
        std::cout << number_1 << " != " << number_2 << " " << (number_1 != number_2) << '\n';
        std::cout << string_1 << " != " << string_2 << " " << (string_1 != string_2) << '\n';
    }

Output:

    [1,2,3] != [1,2,4] true
    {"A":"a","B":"b"} != {"A":"a","B":"b"} false
    17 != 17.0 false
    "foo" != "bar" true

Example

The example demonstrates comparing several JSON types against the null pointer (JSON `null`).

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

    using json = nlohmann::json;

    int main()
    {
        // create several JSON values
        json array = {1, 2, 3};
        json object = {{"A", "a"}, {"B", "b"}};
        json number = 17;
        json string = "foo";
        json null;

        // output values and comparisons
        std::cout << std::boolalpha;
        std::cout << array << " != nullptr " << (array != nullptr) << '\n';
        std::cout << object << " != nullptr " << (object != nullptr) << '\n';
        std::cout << number << " != nullptr " << (number != nullptr) << '\n';
        std::cout << string << " != nullptr " << (string != nullptr) << '\n';
        std::cout << null << " != nullptr " << (null != nullptr) << '\n';
    }

Output:

    [1,2,3] != nullptr true
    {"A":"a","B":"b"} != nullptr true
    17 != nullptr true
    "foo" != nullptr true
    null != nullptr false

## Version history

- Added in version 1.0.0.

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