3.string字符串拼接

#include<iostream>
using namespace std;

//string 字符串拼接
//string& operator+=(const char* s);重载+=操作符
//string& operator+=(const char c);重载+=操作符
//string& operator+=(const string& s);重载+=操作符
//string& append(const char* s);把字符串s连接到当前字符串尾部
//string& append(const char* s,int n);把字符串的前n个字符串连接到当前字符串尾部
//string& append(const string& s);同operator+=（const string& str）
//string& append(const string& s,int pos,int n);字符串s从pos开始的n个字符串连接到字符串结尾

void test0301()
{
    string str1 = "我";

    str1 += "爱玩游戏";

    cout << "str1=" << str1 << endl;

    str1 += ":";
    cout << "str1=" << str1 << endl;

    string str2 = "LOL DNF";

    str1 += str2;
    cout << "str1=" << str1 << endl;

    string str3 = "I";
    str3.append(" LOVE ");
    cout << "str3=" << str3 << endl;

    str3.append("game  abc", 4);
    cout << "str3=" << str3 << endl;

    str3.append(str2);
    cout << "str3=" << str3 << endl;

    str3.append(str2, 0, 3);
    cout << "str3=" << str3 << endl;

}


int main()
{
    test0301();
    system("pause");
    return 0;
}