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# 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 whether one JSON value `lhs` is less than another JSON value `rhs` according to the following rules:

- If `lhs` and `rhs` have the same type, the values are compared using the default `<` operator.
- Integer and floating-point numbers are automatically converted before comparison
- Discarded values a

- In case `lhs` and `rhs` have different types, the values are ignored and the order of the types is considered, which is:

  1. null
  2. boolean
  3. number (all types)
  4. object
  5. array
  6. string
  7. binary

  For instance, any boolean value is considered less than any string.

## 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 `lhs` is less than `rhs`

## Exception safety

No-throw guarantee: this function never throws exceptions.

## Complexity

Linear.

## Example

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 = 17.0000000000001L;
        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 == 17.0000000000001 true
    "foo" == "bar" false

## Version history

- Added in version 1.0.0.