C++语言基础 例程 字符串流

例：“写”字符数组

#include<iostream>
#include <strstream>
using namespace std;
struct student
{
    int num;
    char name[20];
    float score;
};


int main( )
{
    student stud[3]= {1001,"Li",78,1002,"Wang",89.5,1004,"Fun",90};
    char c[50];                //用户定义的字符数组
    ostrstream strout1(c,30);   //建立输出字符串流，与数组c建立关联，缓冲区长30
    for(int i=0; i<3; i++)     //向字符数组c写3个学生的数据
        strout1<<stud[i].num<<stud[i].name<<stud[i].score;
    strout1<<ends;              //ends是C++的I/O操作符，插入一个′\\0′
    cout<<"array c:"<<c<<endl;    //显示字符数组c中的字符
    ostrstream strout2(c,40);  //这时，c将被重写
    for(int i=0; i<3; i++)
        strout2<<stud[i].num<<" "<<stud[i].name<<" "<<stud[i].score<<" ";
    strout2<<ends;              //ends是C++的I/O操作符，插入一个′\\0′
    cout<<"array c:"<<c<<endl;    //显示字符数组c中的字符
    return 0;
}

以字符串流为中介交换数据

#include <strstream>
#include<iostream>
using namespace std;
int main( )
{
    char c[50]="12 34 65 -23 -32 33 61 99 321 32";
    int a[10],i,j,t;
    cout<<"array c:"<<c<<endl;//显示字符数组中的字符串
    istrstream strin(c,sizeof(c));    //建立输入串流对象strin并与字符数组c关联
    for(i=0; i<10; i++)
        strin>>a[i];                     //从字符数组c读入10个整数赋给整型数组a
    cout<<"array a:";
    for(i=0; i<10; i++)
        cout<<a[i]<<" ";                 //显示整型数组a各元素
    cout<<endl;
    for(i=0; i<9; i++)                 //用起泡法对数组a排序
        for(j=0; j<9-i; j++)
            if(a[j]>a[j+1])
            {
                t=a[j];
                a[j]=a[j+1];
                a[j+1]=t;
            }
    ostrstream strout(c,sizeof(c));    //建立输出串流对象strout并与字符数组c关联
    for(i=0; i<10; i++)
        strout<<a[i]<<" ";               //将10个整数存放在字符数组c
    strout<<ends;                      //加入′\\0′
    cout<<"array c:"<<c<<endl;         //显示字符数组c
    return 0;
}