c++输入输出/文件流

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常用流

cin：

cin.get(1/2/3个参数)

cin.get(myInt1).get(myInt2).get(myInt3);

cin.getline()

cin.getline(a,256)

cin.ignore() //去掉一个字符

cin.peek() //只看不读

cin.putback() //放回去一个字符

cout：

cout<<hex<<123<<endl; //16进制显示

cout.flush()

cout.put()

cout.write()

cout.width() //设置占据空间

cout.fill() //填充

cout.fill(‘*’)

cout.setf()

cerr

clog

读写二进制文件

#include<iostream>#include<fstream>using namespace std;class Animal{private:int itsWeight;long DaysAlive;public:Animal(int weight, long days) :itsWeight(weight), DaysAlive(days) {}~Animal(){}int GetWeight() const { return itsWeight; }void SetWeight(int weight) { itsWeight = weight; }long GetDaysAlive() const { return DaysAlive; }void SetDaysAlive(long days) { DaysAlive = days; }};int main(){char fn[255] = "d:\\a.mal";   //可自己定义拓展名ofstream fout(fn,ios::binary);  //打开一个文件if (!fout){cout << "unable to open" << fn << "for writing.\n";return(1);}Animal bear(50, 100);fout.write((char *)&bear, sizeof bear);fout.close();ifstream fin(fn, ios::binary);if (!fin){cout << "unable to open" << fn << "for writing.\n";return(1);}Animal BearTwo(1, 1);fin.read((char *)&BearTwo, sizeof Animal);cout << BearTwo.GetWeight() << endl;cout << BearTwo.GetDaysAlive() << endl;cin.get();return 0;}

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