std::vector<T,Allocator>::front

 

C++

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Technical Specifications

 

Containers library

array (C++11)

vector

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list

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std::vector

Member functions

vector::vector

vector::~vector

vector::operator=

vector::assign

vector::get_allocator

Element access

vector::at

vector::operator[]

vector::front

vector::back

vector::data (C++11)

Iterators

vector::beginvector::cbegin (C++11)

vector::endvector::cend (C++11)

vector::rbeginvector::crbegin (C++11)

vector::rendvector::crend (C++11)

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vector::empty

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vector::emplace_back (C++11)

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Deduction guides(C++17)

 

reference front();
const_reference front() const;

Returns a reference to the first element in the container.

Calling front on an empty container is undefined.

Parameters

(none)

Return value

reference to the first element

Complexity

Constant

Notes

For a container c, the expression c.front() is equivalent to *c.begin().

Example

The following code uses front to display the first element of a std::vector<char>:

Run this code

#include <vector>
#include <iostream>
 
int main()
{
    std::vector<char> letters {'o', 'm', 'g', 'w', 't', 'f'};
 
    if (!letters.empty()) {
        std::cout << "The first character is: " << letters.front() << '\n';
    }  
}

Output:

The first character is o

See also

back	access the last element (public member function)