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std::vector::front

提供: cppreference.com
< cpp‎ | container‎ | vector

 
 
 
std::vector
メンバ関数
Original:
Member functions
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vector::vector
vector::~vector
vector::operator=
vector::assign
vector::get_allocator
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
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vector::at
vector::operator[]
vector::front
vector::back
vector::data(C++11)
イテレータ
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)
容量
Original:
Capacity
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vector::empty
vector::size
vector::max_size
vector::reserve
vector::capacity
vector::shrink_to_fit(C++11)
修飾子
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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;
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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目次

[編集] パラメータ

(なし)
Original:
(none)
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[編集] 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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[編集] 複雑

定数
Original:
Constant
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[編集] ノート

コンテナc、発現c.front()*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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[編集]

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

末尾の要素にアクセスします
(パブリックメンバ関数) [edit]