std::vector::operator[]

 

C++

语言

概念

实用工具库

字符串库

集装箱库

算法库

迭代器库

Numerics库

输入/输出库

本地化库

正则表达式库 （C++11）

原子操作库 （C++11）

线程的支持库 （C++11）

 

容器库

array （C++11）

vector

deque

forward_list （C++11）

list

set

multiset

map

multimap

unordered_set （C++11）

unordered_multiset （C++11）

unordered_map （C++11）

unordered_multimap （C++11）

stack

queue

priority_queue

 

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.

vector::vector

vector::~vector

vector::operator=

vector::assign

vector::get_allocator

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

vector::operator[]

vector::front

vector::back

vector::data （C++11）

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.

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

vector::empty

vector::size

vector::max_size

vector::reserve

vector::capacity

vector::shrink_to_fit （C++11）

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

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       operator[]( size_type pos );
const_reference operator[]( size_type pos ) const;

返回一个引用的元素在指定的位置pos。没有执行边界检查.

Original:

Returns a reference to the element at specified location pos. No bounds checking is performed.

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

参数

pos

-

该元素的位置返回 Original: position of the element to return The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

返回值

参考所需的元素

Original:

reference to the requested element

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

复杂性

常数

Original:

Constant

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

为例

下面的代码使用operator[]读取和写入到std::vector<int>

Original:

The following code uses operator[] read from and write to a std::vector<int>:

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<int> numbers {2, 4, 6, 8};
 
    std::cout << "Second element: " << numbers[1] << '\n';
 
    numbers[0] = 5;
 
    std::cout << "All numbers:";
    for (auto i : numbers) {
        std::cout << ' ' << i;
    }
    std::cout << '\n';
}

Output:

Second element: 4
All numbers: 5 4 6 8

另请参阅

at	访问指定的元素与边界检查 Original: access specified element with bounds checking 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）