std::vector::back

 

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std::vector

成员函数 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.

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元素的访问 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

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

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reference back();
const_reference back() const;

返回的最后一个元素在容器中的参考.

Original:

Returns reference to the last element in the container.

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在一个空容器中调用back是不确定的.....

Original:

Calling back on an empty container is undefined.

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参数

（无）

Original:

(none)

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返回值

参考的最后一个元素

Original:

reference to the last element

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复杂性

常数

Original:

Constant

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注释

对于一个容器c，表达return c.back();相当于{ auto tmp = c.end(); --tmp; return *tmp; }

Original:

For a container c, the expression return c.back(); is equivalent to { auto tmp = c.end(); --tmp; return *tmp; }

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为例

下面的代码使用back显示的最后一个元素的std::vector<char>

Original:

The following code uses back to display the last 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 last character is: " << letters.back() << '\n';
    }
}

Output:

The last character is f

另请参阅

front	访问的第一个元素 Original: access 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. （公共成员函数）