cpp #include #include #include #include #include #include #include #include #include #include #include class AgeCalculator : public QMainWindow { Q_OBJECT public: AgeCalculator(QWidget *parent = nullptr) : QMainWindow(parent) { createGUI(); } private: void createGUI() { // Create main window setWindowTitle("Age Calculator"); setFixedSize(400, 200); // Create input panel QWidget *inputPanel = new QWidget(this); QGridLayout *inputLayout = new QGridLayout(); inputPanel->setLayout(inputLayout); QLabel *birthYearLabel = new QLabel("Birth Year:"); inputLayout->addWidget(birthYearLabel, 0, 0); QLineEdit *birthYearEdit = new QLineEdit(); inputLayout->addWidget(birthYearEdit, 0, 1); QLabel *birthMonthLabel = new QLabel("Birth Month:"); inputLayout->addWidget(birthMonthLabel, 1, 0); QLineEdit *birthMonthEdit = new QLineEdit(); inputLayout->addWidget(birthMonthEdit, 1, 1); QLabel *birthDayLabel = new QLabel("Birth Day:"); inputLayout->addWidget(birthDayLabel, 2, 0); QLineEdit *birthDayEdit = new QLineEdit(); inputLayout->addWidget(birthDayEdit, 2, 1); // Create button panel QWidget *buttonPanel = new QWidget(this); QHBoxLayout *buttonLayout = new QHBoxLayout(); buttonPanel->setLayout(buttonLayout); QPushButton *calculateButton = new QPushButton("Calculate Age"); calculateButton->setFixedWidth(100); buttonLayout->addWidget(calculateButton); QLabel *resultLabel = new QLabel(""); buttonLayout->addWidget(resultLabel); // Create main layout QVBoxLayout *mainLayout = new QVBoxLayout(); mainLayout->addWidget(inputPanel); mainLayout->addWidget(buttonPanel); // Set main layout setCentralWidget(new QWidget(this)); setCentralWidget->setLayout(mainLayout); // Connect button click event connect(calculateButton, &QPushButton::clicked, this, &AgeCalculator::calculateAge); } void calculateAge() { try { int birthYear = birthYearEdit->text().toInt(); int birthMonth = birthMonthEdit->text().toInt(); int birthDay = birthDayEdit->text().toInt(); QDate birthDate(birthYear, birthMonth, birthDay); QDate today = QDate::currentDate(); int age = today.year() - birthDate.year(); if (today.month() < birthDate.month() || (today.month() == birthDate.month() && today.day() < birthDate.day())) { age--; } resultLabel->setText("You are " + QString::number(age) + " years old."); } catch (const std::exception &e) { QMessageBox::critical(this, "Error", "Invalid input. Please enter a valid birth year, month, and day."); } } private: QLineEdit *birthYearEdit; QLineEdit *birthMonthEdit; QLineEdit *birthDayEdit; QLabel *resultLabel; }; int main(int argc, char *argv[]) { QApplication app(argc, argv); AgeCalculator calculator; calculator.show(); return app.exec(); }

mahmudul