# include<iostream>
# include<string>
using namespace std;

void test01()
{
	string str1 = "Hello";
	cout << "str1:" << str1 << endl;
	str1.insert(1, "111");
	cout << "str1:" << str1 << endl;
	str1.erase(1, 3);
	cout << "str1:" << str1 << endl;
}
int main()
{
	test01();
	system("pause");
	return 0;
}