c++ - 对齐输出中的小数位？

Question

#include <iomanip>
#include <cmath>
#include <iostream>
using namespace std;


int main() {
    //
    //HERE IS THE ISSUE
    //set precision to 3 decimals
    cout<<fixed;
    //printing the final pressure of the gas
    cout <<setw(20)<<left<<setfill('.')<<"Equation #01"<<"Ideal Gas Law(Chemistry): "<<setw(5)<<setprecision(3)<<gaslawPressure<<" atm" 
<<endl;

    //printing the calculated distance
    cout <<setw(20)<<left<<setfill('.')<<"Equation #02"<<"Distance Formula(Math): "<<setw(5)<<setprecision(3)<<pointDistance<<endl;
    return 0;
}

给出的输出:

Equation #01........Ideal Gas Law(Chemistry): 1.641 atm
Equation #02........Distance Formula(Math): 30.017

期望的输出:

Equation #01........Ideal Gas Law(Chemistry):    1.641 atm
Equation #02........Distance Formula(Math)  :   30.017

我还需要让冒号对齐。

Answer 1

您必须根据您的文本在不同部分放置适当的 setw 以及左对齐

1)第一部分

setw(20)<<left<<setfill('.')<<"Equation #01" 

2) 第二部分假设它的长度约为 30

setw(30)<<left<<setfill(' ')<<"Ideal Gas Law(Chemistry)"

3) 对齐冒号:

setw(3)<<left<<setfill(' ')<<":"

4)值部分

setw(5)<<std::left<<setprecision(3)<<gaslawPressure<<" atm"



#include <iomanip>
#include <cmath>
#include <iostream>
using namespace std;


int main() {
    //
    //HERE IS THE ISSUE
    //set precision to 3 decimals
    auto gaslawPressure = 1.641;
    auto pointDistance = 30.017;

    cout<<fixed;
    //printing the final pressure of the gas
    cout <<setw(20)<<left<<setfill('.')<<"Equation #01"<<setw(30)<<left<<setfill(' ')<<"Ideal Gas Law(Chemistry)"<<setw(3)<<left<<setfill(' ')<<":"<<setw(5)<<std::left<<setprecision(3)<<gaslawPressure<<" atm"<<endl;

    //printing the calculated distance
    cout <<std::left<<setw(20)<<left<<setfill('.')<<"Equation #02"<<setw(30)<<left<<setfill(' ')<<"Distance Formula(Math)"<<setw(3)<<left<<setfill(' ')<<":"<<setw(5)<<setprecision(3)<<pointDistance<<endl;
    return 0;
}

输出

Equation #01........Ideal Gas Law(Chemistry)      :  1.641 atm
Equation #02........Distance Formula(Math)        :  30.017
Program ended with exit code: 0