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operators (std::array)
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operators (std::unordered_multiset)
operators (std::unordered_set)
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remove_if
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std::array
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std::forward_list::before_begin
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std::forward_list::front
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std::forward_list::max_size
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std::get(std::array)
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std::list
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std::list::list
std::list::max_size
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std::map
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std::multimap::equal_range
std::multimap::erase
std::multimap::extract
std::multimap::find
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std::multimap::key_comp
std::multimap::lower_bound
std::multimap::max_size
std::multimap::merge
std::multimap::multimap
std::multimap::rbegin
std::multimap::rend
std::multimap::size
std::multimap::swap
std::multimap::upper_bound
std::multimap::value_comp
std::multimap::value_compare
std::multiset
std::multiset::begin
std::multiset::cbegin
std::multiset::cend
std::multiset::clear
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std::multiset::crend
std::multiset::emplace
std::multiset::emplace_hint
std::multiset::empty
std::multiset::end
std::multiset::equal_range
std::multiset::erase
std::multiset::extract
std::multiset::find
std::multiset::get_allocator
std::multiset::insert
std::multiset::key_comp
std::multiset::lower_bound
std::multiset::max_size
std::multiset::merge
std::multiset::multiset
std::multiset::rbegin
std::multiset::rend
std::multiset::size
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std::set
std::set::begin
std::set::cbegin
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std::set::clear
std::set::count
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std::set::crend
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std::set::empty
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std::set::equal_range
std::set::erase
std::set::extract
std::set::find
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std::set::insert
std::set::key_comp
std::set::lower_bound
std::set::max_size
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std::set::rend
std::set::set
std::set::size
std::set::swap
std::set::upper_bound
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std::stack
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std::swap(std::list)
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std::swap(std::multiset)
std::swap(std::priority_queue)
std::swap(std::queue)
std::swap(std::set)
std::swap(std::stack)
std::swap(std::unordered_map)
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std::swap(std::unordered_multiset)
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std::tuple_element<std::array>
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std::unordered_map
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std::unordered_map::cend
std::unordered_map::clear
std::unordered_map::count
std::unordered_map::emplace
std::unordered_map::emplace_hint
std::unordered_map::empty
std::unordered_map::end
std::unordered_map::end(int)
std::unordered_map::equal_range
std::unordered_map::erase
std::unordered_map::extract
std::unordered_map::find
std::unordered_map::get_allocator
std::unordered_map::hash_function
std::unordered_map::insert
std::unordered_map::insert_or_assign
std::unordered_map::key_eq
std::unordered_map::load_factor
std::unordered_map::max_bucket_count
std::unordered_map::max_load_factor
std::unordered_map::max_size
std::unordered_map::merge
std::unordered_map::operator[]
std::unordered_map::rehash
std::unordered_map::reserve
std::unordered_map::size
std::unordered_map::swap
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std::unordered_map::unordered_map
std::unordered_multimap
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std::unordered_multimap::bucket
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std::unordered_multimap::end(int)
std::unordered_multimap::equal_range
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std::unordered_multimap::find
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std::unordered_multimap::hash_function
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std::unordered_multimap::key_eq
std::unordered_multimap::load_factor
std::unordered_multimap::max_bucket_count
std::unordered_multimap::max_load_factor
std::unordered_multimap::max_size
std::unordered_multimap::merge
std::unordered_multimap::rehash
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std::unordered_multimap::unordered_multimap
std::unordered_multiset
std::unordered_multiset::begin
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std::unordered_multiset::bucket_count
std::unordered_multiset::bucket_size
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std::unordered_multiset::cbegin
std::unordered_multiset::cend
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std::unordered_multiset::clear
std::unordered_multiset::count
std::unordered_multiset::emplace
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std::unordered_multiset::empty
std::unordered_multiset::end
std::unordered_multiset::end(int)
std::unordered_multiset::equal_range
std::unordered_multiset::erase
std::unordered_multiset::extract
std::unordered_multiset::find
std::unordered_multiset::get_allocator
std::unordered_multiset::hash_function
std::unordered_multiset::insert
std::unordered_multiset::key_eq
std::unordered_multiset::load_factor
std::unordered_multiset::max_bucket_count
std::unordered_multiset::max_load_factor
std::unordered_multiset::max_size
std::unordered_multiset::merge
std::unordered_multiset::rehash
std::unordered_multiset::reserve
std::unordered_multiset::size
std::unordered_multiset::swap
std::unordered_multiset::unordered_multiset
std::unordered_set
std::unordered_set::begin
std::unordered_set::begin(int)
std::unordered_set::bucket
std::unordered_set::bucket_count
std::unordered_set::bucket_size
std::unordered_set::cbegin
std::unordered_set::cbegin
std::unordered_set::cend
std::unordered_set::cend
std::unordered_set::clear
std::unordered_set::count
std::unordered_set::emplace
std::unordered_set::emplace_hint
std::unordered_set::empty
std::unordered_set::end
std::unordered_set::end(int)
std::unordered_set::equal_range
std::unordered_set::erase
std::unordered_set::extract
std::unordered_set::find
std::unordered_set::get_allocator
std::unordered_set::hash_function
std::unordered_set::insert
std::unordered_set::key_eq
std::unordered_set::load_factor
std::unordered_set::max_bucket_count
std::unordered_set::max_load_factor
std::unordered_set::max_size
std::unordered_set::merge
std::unordered_set::rehash
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std::uses_allocator<std::queue>
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std::vector
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std::vector::clear
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std::vector::data
std::vector::emplace
std::vector::emplace_back
std::vector::empty
std::vector::end
std::vector::erase
std::vector::front
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std::vector::insert
std::vector::max_size
std::vector::operator[]
std::vector::pop_back
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std::map::find

STD：：地图：：找到

iterator find( const Key& key (1)​
const_iterator find( const Key& key ) const;(2)​
template< class K > iterator find( const K& x (3)(since C++14)
template< class K > const_iterator find( const K& x ) const;(4)(since C++14)

1，2%29找到一个密钥相当于key...

3，4%29找到一个键比较的元素等价物价值x。此重载仅在下列情况下才参与重载解析：Compare::is_transparent是有效的，并表示类型。它允许调用此函数，而无需构造Key

参数

key-key value of the element to search for
x-a value of any type that can be transparently compared with a key

返回值

元素的迭代器，该元素的密钥等价于key如果没有找到这样的元素，请参阅end()返回%29迭代器。

复杂性

容器大小的对数。

例

二次

#include <iostream>
#include <map>
 
int main()
{  
    std::map<int,char> example = {{1,'a'},{2,'b'}};
 
    auto search = example.find(2
    if(search != example.end()) {
        std::cout << "Found " << search->first << " " << search->second << '\n';
    }
    else {
        std::cout << "Not found\n";
    }
}

二次

产出：

二次

Found 2 b

二次

另见

countreturns the number of elements matching specific key (public member function)
equal_rangereturns range of elements matching a specific key (public member function)

例

演示通过运算符访问不存在元素的风险。[]。

二次

#include <string>
#include <iostream>
#include <map>
 
int main()
{
    std::map<std::string,int> my_map;
    my_map["x"] =  11;
    my_map["y"] = 23;
 
    auto it = my_map.find("x"
    if (it != my_map.end()) std::cout << "x: " << it->second << "\n";
 
    it = my_map.find("z"
    if (it != my_map.end()) std::cout << "z1: " << it->second << "\n";
 
    // Accessing a non-existing element creates it
    if (my_map["z"] == 42) std::cout << "Oha!\n";
 
    it = my_map.find("z"
    if (it != my_map.end()) std::cout << "z2: " << it->second << "\n";
}

二次

产出：

二次

x: 11
z2: 0

二次

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http：//en.cppreference.com/w/cpp/容器/map/find

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