map容器的四种插入元素方法_c++ map添加元素的方法

//插入元素 //四种插入方法比较
void display()
{
	map<int,string> m;
 
	pair<map<int,string>::iterator,bool> pair1 ,pair2,pair3;
 
	//1.方法 
	pair1 = m.insert(pair<int,string>(1,"teacher01"));
	pair2 = m.insert(pair<int,string>(2,"teacher02"));
	pair3 = m.insert(pair<int,string>(2,"teacher02"));
 
	if (pair2.second)
	{
		cout<<"2 teacher02插入成功"<<endl;
		cout<<pair2.first->first<<":"<<pair2.second<<endl;
	}
	else
	{
		cout<<"2 teacher02插入失败"<<endl;
		cout<<pair2.first->first<<":"<<pair2.second<<endl;
	}
 
	if (pair3.second)
	{
		cout<<"2 teacher02插入成功"<<endl;
		cout<<pair3.first->first<<":"<<pair3.second<<endl;
	}
	else
	{
		cout<<"2 teacher02插入失败"<<endl;
		cout<<pair3.first->first<<":"<<pair3.second<<endl;
	}
 
	//2.方法 
 
	m.insert(make_pair(3,"teacher03"));
	m.insert(make_pair(4,"teacher04"));
 
	//3.方法 
	m.insert(map<int,string>::value_type(5,"teacher05"));
	m.insert(map<int,string>::value_type(6,"teacher06"));
 
	//4. 如果key相等 会修改对应的value 
	m[7] = "teacher07";
	m[8] = "teacher08";
	m[0] = "teacher09";
	m[0] = "teacher00";
 
	//遍历
	for (map<int,string>::iterator it = m.begin();it!=m.end();it++)
	{
		cout<<(*it).first<<endl;
		cout<<(*it).second<<endl;
	}
	while (!m.empty())
	{
		map<int,string>::iterator it = m.begin();
		cout<<it->first<<"\t"<<it->second<<endl;
		m.erase(it);
	}
}