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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 or equal to another JSON value rhs by calculating #cpp !(rhs < lhs).

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 or equal to 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"} true
17 <= 17.0000000000001 true
"foo" <= "bar" false

Version history

  • Added in version 1.0.0.