C++ set end()函数用于返回迭代器,该迭代器位于集合中最后一个元素。
iterator end(); //until C++ 11 const_iterator end() const; //until C++ 11 iterator end() noexcept; //since C++ 11 const_iterator end() const noexcept; //since C++ 11
它返回一个迭代器,该迭代器指向集合的最后一个元素。
让我们看一下end()函数的简单示例:
#include <iostream> #include <set> using namespace std; int main () { set<string> myset = {"Java", "C++", "SQL"}; //show content: for (set<string>::iterator it=myset.begin(); it!=myset.end(); ++it) cout << *it<< '\n'; return 0; }
输出:
C++ Java SQL
在上面的示例中,end()函数用于返回指向myset集合中最后一个元素旁边的迭代器。
让我们看一个简单的示例,使用for-each循环遍历集合:
#include <iostream> #include <set> using namespace std; int main() { set<int> c; c.insert(5); c.insert(2); c.insert(4); c.insert(1); c.insert(0); c.insert(0); c.insert(9); set<int>::iterator i = c.begin(); while (i != c.end()) cout << *i++ << " "; cout << endl; }
输出:
0 1 2 4 5 9
让我们看一个简单的示例,使用while循环遍历集合:
#include <iostream> #include <set> #include <string> int main() { using namespace std; set<string> myset = { "Nikita","Deep","Priya","Suman","Aman" }; cout<<"Elements of myset are: "<<endl; set<string>::const_iterator it;//declare an iterator it = myset.begin();//assign it to the start of the set while (it != myset.end())//while it hasn't reach the end { cout << *it << "\n"; // print the value of the element it points to ++it;//and iterate to the next element } cout << endl; }
输出:
Elements of myset are: Aman Deep Nikita Priya Suman
在上面的示例中,end()函数用于返回指向myset集合中最后一个元素旁边的迭代器。
让我们看一个简单的例子:
#include <iostream> #include <string> #include <set> using namespace std; int main () { int val; set<int> c = {10,20,30,40,50}; cout<<"Enter value to find: "; cin>>val; auto result = c.find(val); //find until end of the set elements if (result != c.end()) { cout << "Element found: "<< *result; cout << endl; } else { cout << "Element not found." << endl; } return 0; }
输出:
Enter value to find: 60 Element not found. Enter value to find: 30 Element found: 30
在上面的示例中,end()函数用于返回指向myset集合中最后一个元素旁边的迭代器。
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