std::basic_string<CharT,Traits,Allocator>::begin, std::basic_string<CharT,Traits,Allocator>::cbegin

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basic_string::beginbasic_string::cbegin
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iterator begin();
(1) (noexcept since C++11)
(constexpr since C++20)
const_iterator begin() const;
(2) (noexcept since C++11)
(constexpr since C++20)
const_iterator cbegin() const noexcept;
(3) (since C++11)
(constexpr since C++20)

Returns an iterator to the first character of the string.

begin() returns a mutable or constant iterator, depending on the constness of *this.

cbegin() always returns a constant iterator. It is equivalent to const_cast<const basic_string&>(*this).begin().

range-begin-end.svg

Parameters

(none)

Return value

Iterator to the first character.

Complexity

Constant.

Notes

libc++ backports cbegin() to C++98 mode.

Example

#include <iostream>
#include <string>
 
int main()
{
    std::string s("Exemplar");
    *s.begin() = 'e';
    std::cout << s << '\n';
 
    auto i = s.cbegin();
    std::cout << *i << '\n';
//  *i = 'E'; // error: i is a constant iterator
}

Output:

exemplar
e

See also

(C++11)
returns an iterator to the end
(public member function)
returns an iterator to the beginning
(public member function of std::basic_string_view<CharT,Traits>)