std::vector::front

 

C++

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std::vector

メンバ関数 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.

vector::vector

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要素アクセスの循環参照を解除するために使用されている 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.

vector::at

vector::operator[]

vector::front

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

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

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reference front();
const_reference front() const;

コンテナ内の最初の要素への参照を返します.

Original:

Returns a reference to the first element in the container.

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空の容器にfrontを呼び出すと、定義されていません.

Original:

Calling front on an empty container is undefined.

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パラメータ

（なし）

Original:

(none)

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値を返します

最初の要素への参照

Original:

reference to the first element

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複雑

定数

Original:

Constant

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ノート

コンテナc、発現c.front()は*c.begin()と同等です.

Original:

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

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例

次のコードは、frontの最初の要素を表示するためにstd::vector<char>を使用しています

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

back	末尾の要素にアクセスします (パブリックメンバ関数)