C++学习——四种字符串与数据连接的方法

#include <iostream>
#include <string>
#include <cstdlib>
#include <sstream>
#include <cstring> 
using namespace std;
//第一种C风格的转化(以前一直喜欢的  sprintf 功能强大)
void test()
{
    char *s = "dong";
    int a = 52;
    float b = .1314;
    char *buf = new char[strlen(s) + sizeof(a) + 1];
    sprintf(buf, "%s%d%.4f", s, a, b);
    printf("%s\n", buf);
}
//半C半C++风格
void test1()
{
    string s = "dong";
    int a = 520;
    char *buf = new char[10];//2147483647 int最大值
    _itoa(a, buf, 10);      //itoa虽然可以转化为各种进制，但是注意不能是float或者double
    cout << s + buf << " | ";
    _itoa(a, buf, 16);
    cout << s + buf << endl;
}
//纯C++风格
void test2()
{
    string s = "陈明东";
    int a = 52;
    double b = .1314;
    ostringstream oss;
    oss << s << a << b;
    cout << oss.str() << endl;
}
//C++11新特性
void test3()
{
    int a = 520;
    float b = 5.20;
    string str = "dong";
    string res = str + to_string(a);
    cout << res << endl;
    res = str + to_string(b);
    res.resize(8);
    cout << res << endl;
}
int main()
{
    test();
    test1();
    test2();
    test3();
    return 0;
}