9_4.cpp

c++书籍的源代码

#include<iostream.h>
 int main()
{
 int a=30;
 long oldf;
 float b=3.1415926;
 cout.width(5);
 oldf=cout.flags(ios::left|ios::hex|ios::showbase|ios::uppercase);
 cout<<a<<endl;//输出a的值
 cout.flags(oldf);//恢复原先设置 
 cout.width(5);
 cout.fill('#'); 
 cout.setf(ios::internal);
 cout.setf(ios::oct|ios::showbase);
 cout<<a<<endl;//输出a的值
 cout.fill(' '); 
 cout.unsetf(ios::internal);//取消设置
 cout.unsetf(ios::oct|ios::showbase);//取消设置
 cout.width(15);
 cout.setf(ios::scientific);
 cout.setf(ios::showpos);
 cout.precision(5);//设置精度 
 cout<<b<<endl;
 cout.setf(ios::fixed,ios::floatfield);//重新设置浮点数输出形式
 cout.unsetf(ios::showpos);//取消设置
 cout.width(10);
 cout.precision(6);//设置精度
 cout<<b<<endl;
 cout.unsetf(ios::fixed);//取消设置
 cout.setf(ios::showpoint);
 cout.width(10);
 cout.precision(5);//设置精度
 cout<<b<<endl;
 return(0);
}