setprec.cpp

高永强 全C编程源码 清华大学出版社 2002年六月第一版

//这个程序在本书所带软盘中，文件名为SETPREC.CPP
//这个程序用浮点精度控制操作setprecision()来控制小数位数的输出

#include <iostream.h>
#include <iomanip.h>            //这个头文件支持浮点精度控制操作setprecision()

void main(void)
{
	cout << setprecision(0);
	cout << 2.2/7.0 << endl;
	cout << 22.0/7.0 << endl;
	cout << 220.0/7.0 << endl;
	cout << -220.0/7.0 << endl << endl;

	cout << setprecision(1);    //与setprecision(0)相同
	cout << 2.2/7.0 << endl;
	cout << 22.0/7.0 << endl;
	cout << 220.0/7.0 << endl;
	cout << -220.0/7.0 << endl << endl;

	cout << setprecision(2);
	cout << 2.2/7.0 << endl;
	cout << 22.0/7.0 << endl;
	cout << 220.0/7.0 << endl;
	cout << -220.0/7.0 << endl << endl;

	cout << setprecision(3);
	cout << 2.2/7.0 << endl;
	cout << 22.0/7.0 << endl;
	cout << 220.0/7.0 << endl;
	cout << -220.0/7.0 << endl;
}