std::vector<T,Allocator>::begin, std::vector<T,Allocator>::cbegin

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::vector

Member types
Member functions
vector::vector vector::~vector vector::operator= vector::assign vector::assign_range (C++23)   vector::get_allocator Element access vector::operator[] vector::at vector::data vector::front vector::back Iterators vector::beginvector::cbegin (C++11) vector::endvector::cend (C++11) vector::rbeginvector::crbegin (C++11) vector::rendvector::crend (C++11)	Capacity vector::empty vector::size vector::max_size vector::reserve vector::capacity vector::shrink_to_fit (DR*) Modifiers vector::clear vector::erase vector::insert vector::insert_range (C++23) vector::append_range (C++23) vector::emplace (C++11) vector::emplace_back (C++11) vector::push_back vector::pop_back vector::resize vector::swap
Non-member functions
operator==operator<=> (C++20) swap(std::vector) erase(std::vector)erase_if(std::vector) (C++20)(C++20)	operator!=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides(C++17)

 

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 element of the vector.

If the vector is empty, the returned iterator will be equal to end().

Parameters

(none)

Return value

Iterator to the first element.

Complexity

Constant.

Notes

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

Example

Run this code

#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <vector>
 
int main()
{
    std::vector<int> nums{1, 2, 4, 8, 16};
    std::vector<std::string> fruits{"orange", "apple", "raspberry"};
    std::vector<char> empty;
 
    // Print vector.
    std::for_each(nums.begin(), nums.end(), [](const int n) { std::cout << n << ' '; });
    std::cout << '\n';
 
    // Sums all integers in the vector nums (if any), printing only the result.
    std::cout << "Sum of nums: "
              << std::accumulate(nums.begin(), nums.end(), 0) << '\n';
 
    // Prints the first fruit in the vector fruits, checking if there is any.
    if (!fruits.empty())
        std::cout << "First fruit: " << *fruits.begin() << '\n';
 
    if (empty.begin() == empty.end())
        std::cout << "vector 'empty' is indeed empty.\n";
}

Output:

1 2 4 8 16
Sum of nums: 31
First fruit: orange
vector 'empty' is indeed empty.

See also

endcend (C++11)	returns an iterator to the end (public member function)
begincbegin (C++11)(C++14)	returns an iterator to the beginning of a container or array (function template)