功能描述：
按条件查找元素 #include <iostream> #include <functional> #include <vector> #include <string> using namespace std; //内置数据类型 class GreaterFive { public: bool operator()(int val) { return val > 5; } }; void test01() { vector<int> v; for (int i = 0; i < 10; ++i) { v.push_back(i+1); } vector<int>::iterator it = find_if(v.begin(), v.end(), GreaterFive()); if (it == v.end()) { cout << "没有找到" << endl; } else { cout << "找到大于5的数字" << endl; } } //自定义数据类型 class Person { public: Person(string name, int age) { this->m_Name = name; this->m_Age = age; } public: string m_Name; int m_Age; }; class Greater20 { public: bool operator()(Person& p) { return p.m_Age > 20; } }; void test02() { vector<Person> v; //创建数据 Person p1("aaa", 10); Person p2("bbb", 20); Person p3("ccc", 30); Person p4("ddd", 40); v.push_back(p1); v.push_back(p2); v.push_back(p3); v.push_back(p4); vector<Person>::iterator it = find_if(v.begin(), v.end(), Greater20()); if(it == v.end()) { cout << "没有找到！" << endl; } else { cout << "找到姓名： " << it->m_Name << "年龄： " << it->m_Age << endl; } } int main() { //test01(); test02(); return 0; }C++常用查找算法-find_if()
