◐ Shell
clean mode source ↗

std::vector::front – cppreference.com

Aus cppreference.com

<metanoindex/>

<tbody> </tbody>

reference front();

const_reference front() const;

Eine Referenz auf das erste Element in dem Behälter .

Original:

Returns a reference to the first element in the container.

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

Aufruf front auf einem leeren Behälter undefined .

Original:

Calling front on an empty container is undefined.

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

Parameter

(None)

Original:

(none)

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

Rückgabewert

Verweisen auf das erste Element

Original:

reference to the first element

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

Komplexität

Constant

Original:

Constant

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

Notes

Für einen Behälter c ist die Expression c.front() entspricht *c.begin() .

Original:

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

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

Beispiel

Der folgende Code verwendet front um das erste Element einer std::vector<char> anzuzeigen:

Original:

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

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

#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:

See also

Zugriff auf das letzte Element
(öffentliche Elementfunktion) [edit]