nlohmann::basic_json::begin¶

iterator begin() noexcept;
const_iterator begin() const noexcept;

Returns an iterator to the first element.

Illustration from cppreference.com

Return value¶

iterator to the first element

Exception safety¶

No-throw guarantee: this member function never throws exceptions.

Complexity¶

Constant.

Examples¶

Example

The following code shows an example for begin().

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

using json = nlohmann::json;

int main()
{
    // create an array value
    json array = {1, 2, 3, 4, 5};

    // get an iterator to the first element
    json::iterator it = array.begin();

    // serialize the element that the iterator points to
    std::cout << *it << '\n';
}

Output:

Version history¶

Added in version 1.0.0.

Last update: May 1, 2022