Most frequently asked Qt Interview Questions

Define Qt?
Name some of the Development Tools of Qt?
What are the two types GUI application available in QT?
What is Qmake?
Why Qt is misusing view terminology?
What Is Qt And Qml?
What is a slot? How it differs with callback Method?
What are the objects based on meta-object system?
What is the difference between QImage and QPixmap?

Define Qt?

Qt is widely used in developing application software that will be running on various software and hardware platforms.It is a cross platform application framework, used for creating UI , networking, multi thread programming, etc.Qt is comprised of several classes from the Qt object model.

Name some of the Development Tools of Qt?

Qt QmlLive helps in reducing the time takes in deploying and test changes in the UI design.
GammaRay helps in providing introspection tool.
Emulator helps in providing emulation of a target device to test.
Qt Creator helps in creating applications for multiple desktop.
qmake helps in simplifying the building process.
qmlcachegen helps to enable building Qt quick applications without deploying the QML sources.
Qt Assistant> helps in viewing Qt documentation.

What are the two types GUI application available in QT?

Widget based
Qt Quick App

What is Qmake?

Qmake helps in automating the generation of Makefiles, also used by the program make to build executable programs from the source code.
Qmake is a utility which uses information stored in the project files.It is used in software project, whether it is written in Qt or not.It helps in creating standard GNU make files under windows we can generate visual studio can make files and can generate Xcode project files.

Why Qt is misusing view terminology?

What Is Qt And Qml?

Qt and Qml helps in developing applications and libraries with Qml language, it defines and implements language and engine infratructureby providing an API for enabling application developers.It is known as a declarative language for designing users interface application.

What is a slot? How it differs with callback Method?

A slot are virtual cases used when a signal is connected to when it is emitted.We can connect more that one signal in a single slot, whenever one of those connected single is emitted.As Callbacks helps in processing functions with the correct arguments.

What are the objects based on meta-object system?

QObject class helps in providing base class for objects.
Q_OBJECT macro helps in enabling meta objects features.
Meta-Object Compiler helps in implementing meta object features.

What is the difference between QImage and QPixmap?

QImage
It is used as an off screen image.
Used as a paint device.
QPixmap
It is used for providing hardware-independent image.
Allows direct access to pixel data.