10.C++(文件流,标准模板库)

(创建于2018/1/1)

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

//操作文本文件
void writereadtext() {
    //写入文本到一个文件中并创建这个文件,然后读取写入的内容显示到控制台

    char* fname = "D://renzhenming.txt";
    //创建输入流
    ofstream fout(fname);
    //创建失败
    if (fout.bad()) {
        return;
    }
    //写入
    fout << "jack" << endl;
    fout << "rose" << endl;
    //关闭
    fout.close();

    //读取
    ifstream fin(fname);
    if (fin.bad()) {
        return;
    }
    char ch;
    while (fin.get(ch)) {
        //输出
        cout << ch;
    }
    fin.close();
}

//复制二进制文件(图片)
void copyBinaryFile() {
    char *src = "D://beauty.jpg";
    char *des = "D://beauty_copy.jpg";

    //二进制文件使用binary
    ifstream fin(src,ios::binary);
    ofstream fout(des, ios::binary);

    if (fin.bad() || fout.bad()) {
        return;
    }

    while (!fin.eof()) {
        char buff[1024] = {0};
        fin.read(buff, 1024);
        fout.write(buff, 1024);
    }

    fin.close();
    fout.close();
}


class Person
{
public:
    Person()
    {

    }
    Person(char * name, int age)
    {
        this->name = name;
        this->age = age;
    }
    void print()
    {
        cout << name << "," << age << endl;
    }
private:
    char * name;
    int age;
};
//对象持久化
void save_object() {
    Person p1("renzhenming",27);
    Person p2("wuzizi", 26);

    //写入
    ofstream fout("D://obj.data", ios::binary);
    fout.write((char *)(&p1), sizeof(Person));
    fout.write((char*)(&p2), sizeof(Person));
    fout.close();

    //读出
    ifstream fin("D://obj.data", ios::binary);
    Person temp;
    fin.read((char*)(&temp), sizeof(Person));
    temp.print();

    fin.read((char*)(&temp), sizeof(Person));
    temp.print();
}

//标准模板库
#include<string>
void stl() {
    string s1 = "haha";
    string s2(" sha bi");
    string s3 = s1 + s2;
    cout << s3 << endl;

    //转c字符串
    const char * str = s3.c_str();
    cout << str << endl;
}

//容器
#include<vector>
void c_list() {
    vector<int> v;
    v.push_back(12);
    v.push_back(11);
    v.push_back(10);

    for (int i = 0; i < v.size(); i++) {
        cout << v[i] << endl;
    }
}
void main() {
    //writereadtext();
    //copyBinaryFile();
    //save_object();
    //stl();
    c_list();
    system("pause");
}
上一篇:阿里云数据库团队核心亮相M17 揭秘AliSQL、MariaDB合作细节


下一篇:《大数据架构和算法实现之路:电商系统的技术实战》——1.7 更多的思考