简谈c++小数点精确控制

写了很多遍，一直爱忘记，索性写一篇记下来，再者第一次发的这个月也凑个4篇文章了哈哈~

1.头文件 

#include<iostream>

2.精确到小数点后面n位

cout<<setprecision(n)<<fixed<<输出的内容

示例代码

#include<iostream>#include<iomanip>using namespace std;int main(){int a = 1;double b = 1.234;//setprecisioncout << "a: "<<a << "b: " << b << endl;cout << setprecision(2) << "b: " << b << " a: " << a << endl;cout << setprecision(2) << "a: "<<a << " b: " << b << endl;//小数点加fixedcout << setprecision(2) << fixed << "b: " << b << " a: " << a << endl;cout << setprecision(2) << fixed << "a: " << a << " b: " << b << endl;}

结果图如下：