[QT] QT after addition, subtraction, multiplication and division, two decimal places are reserved

【 scene 】

To achieve 10.00 - 5.00 The result is equal to 5.00 Instead of being equal to 5
Because it is an integer just after subtraction , Want to keep two decimal places , You can't keep it directly , Even with double Save the data

【 Method 】

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <iostream>
#include <math.h>
#include <iomanip>

using namespace std;
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    
    ui->setupUi(this);
    double a = 10.00;
    double b = 5.00;
    double c = (a-b);
    cout << setiosflags(ios::fixed) << setprecision(2) << c << endl;
}

MainWindow::~MainWindow()
{
    
    delete ui;
}

result

【 Add 】

You can also use c Methods , direct %l2f Save two decimal places