在c ++中显示小数点后的两位数[重复]

This question already has an answer here:

这个问题在这里已有答案:

Printing the correct number of decimal points with cout 11 answers

使用cout 11答案打印正确的小数点数

Similar topic is already discussed in the forum. But I have some different problem in following code:

论坛已经讨论过类似的话题。但是我在下面的代码中有一些不同的问题:

double total;
cin >> total;
cout << fixed << setprecision(2) << total;

If I give input as 100.00 then program prints just 100 but not 100.00

如果我输入为100.00,那么程序打印只有100而不是100.00

How can I print 100.00?

我怎么打印100.00?

5 个解决方案

#1

cout << fixed << setprecision(2) << total;

setprecision specifies the minimum precision. So

setprecision指定最小精度。所以

cout << setprecision (2) << 1.2;

will print 1.2

将打印1.2

fixed says that there will be a fixed number of decimal digits after the decimal point

fixed表示小数点后面会有一个固定的小数位数

cout << setprecision (2) << fixed << 1.2;

will print 1.20

将打印1.20

#2

The easiest way to do this, is using cstdio's printf. Actually, i'm surprised that anyone mentioned printf! anyway, you need to include the library, like this...

最简单的方法是使用cstdio的printf。实际上,我很惊讶有人提到printf!无论如何,你需要包括库,像这样......

#include<cstdio>

int main() {
    double total;
    cin>>total;
    printf("%.2f\n", total);
}

This will print the value of "total" (that's what %, and then ,total does) with 2 floating points (that's what .2f does). And the \n at the end, is just the end of line, and this works with UVa's judge online compiler options, that is:

这将打印“total”的值(即%,然后,总值),带有2个浮点(这就是.2f的作用)。而最后的\ n只是行尾,这适用于UVa的判断在线编译器选项,即:

g++ -lm -lcrypt -O2 -pipe -DONLINE_JUDGE filename.cpp

the code you are trying to run will not run with this compiler options...

您尝试运行的代码将无法使用此编译器选项运行...

#3

It is possible to print a 15 decimal number in C++ using the following:

可以使用以下代码在C ++中打印15位十进制数:

#include <iomanip>
#include <iostream>

cout << fixed << setprecision(15) << " The Real_Pi is: " << real_pi << endl;
cout << fixed << setprecision(15) << " My Result_Pi is: " << my_pi << endl;
cout << fixed << setprecision(15) << " Processing error is: " << Error_of_Computing << endl;
cout << fixed << setprecision(15) << " Processing time is: " << End_Time-Start_Time << endl;
_getch();

return 0;

#4

This will be possible with setiosflags(ios::showpoint).

setiosflags(ios :: showpoint)可以实现这一点。

#5

Using header file stdio.h you can easily do it as usual like c. before using %.2lf(set a specific number after % specifier.) using printf().

使用头文件stdio.h,您可以像往常一样轻松地执行此操作。在使用%。2lf(在%说明符之后设置一个特定的数字。)之前使用printf()。

It simply printf specific digits after decimal point.

它只是在小数点后打印特定的数字。

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
   double total=100;
   printf("%.2lf",total);//this prints 100.00 like as C
}

#1

cout << fixed << setprecision(2) << total;