如何在输出控制台中显示更多小数？
问题描述：
我想输出全精度的double值。但是，使用cout函数时，即使精度为15-16位左右，它也只显示前6位数字。
I want to output the value of a double in it's full precision. However, when using the cout function, it only displays the first 6 digits even though there is around 15-16 digits of precision.
如何让我的程序显示整个值，包括幅度（幂）分量？
How do I get my program to display the entire value, including the magnitude (power) component?
答
使用 setprecision（）机械手：
http://www.cplusplus.com/reference/iostream/manipulators/setprecision/
您也可以使用 scientific 机械手来强制使用科学计数法：
You can also force scientific notation with the scientific manipulator:
http://www.cplusplus.com/reference/iostream/manipulators/scientific/
cout << scientific << setprecision(15) << my_number << endl;