Namespace
Varianti

std::vector::front

Da cppreference.com.
< cpp‎ | container‎ | vector

 
 
 
std::vector
Membri funzioni
Original:
Member functions
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vector::vector
vector::~vector
vector::operator=
vector::assign
vector::get_allocator
Elemento accesso
Original:
Element access
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vector::at
vector::operator[]
vector::front
vector::back
vector::data(C++11)
Iteratori
Original:
Iterators
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vector::begin
vector::cbegin

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

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

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

(C++11)
Capacità
Original:
Capacity
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vector::empty
vector::size
vector::max_size
vector::reserve
vector::capacity
vector::shrink_to_fit(C++11)
Modificatori
Original:
Modifiers
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vector::clear
vector::insert
vector::emplace(C++11)
vector::erase
vector::push_back
vector::emplace_back(C++11)
vector::pop_back
vector::resize
vector::swap
 
reference front();
const_reference front() const;
Restituisce un riferimento al primo elemento nel contenitore.
Original:
Returns a reference to the first element in the container.
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Chiamare front su un contenitore vuoto non è definito.
Original:
Calling front on an empty container is undefined.
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Indice

[modifica] Parametri

(Nessuno)
Original:
(none)
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[modifica] Valore di ritorno

riferimento al primo elemento
Original:
reference to the first element
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[modifica] Complessità

Constant
Original:
Constant
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[modifica] Note

Per un c contenitore, il c.front() espressione è equivalente a *c.begin().
Original:
For a container c, the expression c.front() is equivalent to *c.begin().
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[modifica] Esempio

Il codice seguente utilizza front per visualizzare il primo elemento di un std::vector<char>:
Original:
The following code uses front to display the first element of a std::vector<char>:
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#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

access the last element
(membro pubblico funzione) [edit]