Experiment 4 QT

	#include "mainwindow.h"
	#include "ui_mainwindow.h"
	
	MainWindow::MainWindow(QWidget *parent) :
	    QMainWindow(parent),
	    ui(new Ui::MainWindow)
	{
    
	    ui->setupUi(this);
	}
	
	MainWindow::~MainWindow()
	{
    
	    delete ui;
	}
	
	void MainWindow::on_get_ans_clicked()
	{
    
	    ui->m_ans->setText("");
	    if(ui->m_x->text().isEmpty()||ui->m_y->text().isEmpty()) return ;
	
	    bool ok=false;
	    int x=ui->m_x->text().toInt(&ok);
	    if(!ok) {
    
	        ui->m_x->setText("");
	        return ;
	    }
	    ok=false;
	    int y=ui->m_y->text().toInt(&ok);
	    if(!ok) {
    
	        ui->m_y->setText("");
	        return ;
	    }
	
	    QString op=ui->m_op->text();
	    if(op=="+") {
    
	        ui->m_ans->setText(QString::number(x+y));
	    } else if(op=="-") {
    
	        ui->m_ans->setText(QString::number(x-y));
	    } else if(op=="*") {
    
	        ui->m_ans->setText(QString::number(x*y));
	    } else if(op=="/") {
    
	        if(y==0) ui->m_ans->setText("diverror");
	        else ui->m_ans->setText(QString::number(x/y));
	    } else if(op=="^") {
    
	        int ans=1;
	        for(int i=0;i<y;i++) ans*=x;
	        ui->m_ans->setText(QString::number(ans));
	    } else if(op=="%") {
    
	        ui->m_ans->setText(QString::number(x%y));
	    } else {
    
	        ui->m_ans->setText("ERROR");
	    }
	    return ;
	}
	
	void MainWindow::on_exit_clicked()
	{
    
	    close();
	    return ;
	}