std::list::front

<metanoindex/>

 

C++

Linguaggio

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Localizzazione

Espressioni regolari (C++11)

Operazioni atomicche (C++11)

Multithreading (C++11)

 

Contenitori libreria

array (C++11)

vector

deque

forward_list (C++11)

list

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map

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unordered_set (C++11)

unordered_multiset (C++11)

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std::list

Membri funzioni Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::list

list::~list

list::operator=

list::assign

list::get_allocator

Elemento accesso Original: Element access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::front

list::back

Iteratori Original: Iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::begin list::cbegin (C++11)

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

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

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

Capacità Original: Capacity The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::empty

list::size

list::max_size

Modificatori Original: Modifiers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::clear

list::insert

list::emplace (C++11)

list::erase

list::push_front

list::emplace_front (C++11)

list::pop_front

list::push_back

list::emplace_back (C++11)

list::pop_back

list::resize

list::swap

Operazioni Original: Operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

list::merge

list::splice

list::remove list::remove_if

list::reverse

list::unique

list::sort

 

<tbody> </tbody>

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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Parametri

(Nessuno)

Original:

(none)

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Valore di ritorno

riferimento al primo elemento

Original:

reference to the first element

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Complessità

Constant

Original:

Constant

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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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Esempio

Il codice seguente utilizza front per visualizzare il primo elemento di un std::list<char>:

Original:

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

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#include <list>
#include <iostream>
 
int main()
{
    std::list<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 (metodo pubblico)