double类型显示问题 设置显示小数点位数

关于double类型显示的一些问题。

void print_double(){    char input;    double number = 1234.56789,weight = 130.645789,height = 168,        six = 666666.66666;         cout<<"original data:\n";    cout<<number<<" "<<weight<<" "<<height<<" "<<six<<endl;    //double输出时，默认显示6位数据,并且会4舍五入    //如果是1.00则会显示1；    cout.setf(ios::fixed);    cout.setf(ios::showpoint);    cout.precision(2);    //以上3行为设置double型变量所显示小数点后的位数    cout<<"precision(2) data:\n";    cout<<number<<" "<<weight<<" "<<height<<endl;    cout.precision(3);    cout<<"precision(3) data:\n";    cout<<number<<" "<<weight<<" "<<height<<endl;    cout.precision(4);    cout<<"precision(4) data:\n";    cout<<number<<" "<<weight<<" "<<height<<endl;    cin>>input;}