json/api/basic_json/cbegin.md

nlohmann::basic_json::cbegin

const_iterator cbegin() const noexcept;

Returns an iterator to the first element.

`cbegin()` points to the first element, like `begin()`, and `end()` to the position after the last element; the dashed cell is the past-the-last position, which must not be dereferenced.

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 `cbegin()`.

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

using nlohmann::json;

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

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

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

```

Output:

```json
1

```

See also

• begin - returns an iterator to the first element
• cend - returns a const iterator to one past the last element
• crbegin - returns a const reverse iterator to the last element
• Iterators - the article on iterators
• basic_json_view::cbegin - the same iteration on a zero-copy view

Version history

• Added in version 1.0.0.