main.cpp

#include "main.h"window::window(QWidget *parent) : QWidget(parent){	txtnum1 = new QLineEdit;	txtnum2 = new QLineEdit;	txtans = new QLineEdit;	buttoncalc = new QPushButton("DO IT!");	buttonexit = new QPushButton("Exit");				txtans->setReadOnly(true);	connect(buttonexit,SIGNAL(clicked()),qApp,SLOT(quit()));	connect(buttoncalc,SIGNAL(clicked()),this,SLOT(calculate()));		//final layout		QVBoxLayout *layout = new QVBoxLayout;	layout->addWidget(txtnum1);	layout->addWidget(txtnum2);	layout->addWidget(txtans);	layout->addWidget(buttoncalc);	layout->addWidget(buttonexit);	setLayout(layout);}void window::calculate(){	int num1,num2,ans;	bool ok;		num1=txtnum1->text().toInt(&ok,10);	num2=txtnum2->text().toInt(&ok,10);	ans=num1*num2;	txtans->setText(QString::number((long)ans,10));}int main(int argc,char* argv[]){	QApplication app(argc,argv);	window mainapp;	mainapp.show();		return app.exec();}