Bentley Systems Graduate Engineer Interview Questions and Answers

There are two ways to throw an exception in exception handling.

• Exceptions can be thrown using the throw keyword.

• Exceptions can also be thrown implicitly by the runtime system.

• Examples of explicit throwing include throw new Exception() and throw new IOException().

• Examples of implicit throwing include division by zero or null pointer dereference.

Reverse a given string using array of characters.

• Create an empty array to store the reversed string.

• Loop through the original string from end to start.

• Push each character into the empty array.

• Join the array to form the reversed string.

Copy constructor creates a new object by copying an existing object, while assignment operator assigns the value of an existing object to another object.

• Copy constructor is used to initialize a new object with the values of an existing object.

• Assignment operator is used to assign the value of an existing object to another object.

• Copy constructor is called when a new object is created from an existing object.

• Assignment ...read more

A copy constructor is used to create a new object with the same values as an existing object. We implement our own to ensure proper copying of data members.

• A copy constructor is needed when we want to create a new object with the same values as an existing object.

• If we don't implement our own copy constructor, the default copy constructor provided by the compiler may not copy data members properly.

• We can implement our ...read more

QT framework is used for developing cross-platform applications with a single codebase.

• QT provides a wide range of libraries and tools for developing GUI applications.

• QT supports multiple platforms including Windows, Linux, macOS, Android, and iOS.

• QT has a large community and extensive documentation.

• QT is written in C++ and supports other programming languages like Python and Java.

• QT is used by companies like Autodesk,...read more

RTTI stands for Run-Time Type Identification.

• RTTI is a feature in C++ that allows the type of an object to be determined at runtime.

• It is used to implement dynamic_cast, typeid, and exception handling.

• RTTI can be used to check if an object is of a certain type before casting it.

• It can also be used to determine the type of an object in order to perform specific operations on it.

I have used the Singleton and Factory design patterns in my previous projects.

• Singleton pattern was used to ensure only one instance of a class is created and provide a global point of access to it.

• Factory pattern was used to create objects without exposing the instantiation logic to the client and provide a way to create objects of a family without specifying their concrete classes.

QT supports multiple operating systems and cross-compilation is possible.

• QT supports Windows, macOS, Linux, Android, iOS, and many other operating systems.

• Cross-compilation is possible, meaning you can compile for different operating systems on a single machine.

• QT also supports embedded systems like Raspberry Pi and BeagleBone.

• QT provides pre-built binaries for some operating systems, but for others, you may need to co...read more

QPointer is a deprecated Qt class used for storing and managing pointers.

• QPointer is used to avoid dangling pointers in Qt applications.

• It is a template class that can be used with any QObject-derived class.

• QPointer is now deprecated and replaced by QWeakPointer.

• QPointer can be used to check if a QObject is still valid before accessing it.

dpointer is a Qt framework concept used for efficient memory management.

• dpointer is a private implementation pointer.

• It is used to hide implementation details from the public API.

• dpointer allows for copy-on-write semantics.

• It reduces memory usage and improves performance.

• Example: QString uses dpointer to store its data.

• Example: QSharedDataPointer is used to share data between objects.

I have used Qt version 5.12.3 for my previous project.

• Qt version 5.12.3 was used in my previous project

• I have experience working with Qt 5.15.2 as well

• I am familiar with the features and functionalities of Qt 5.12.3

To check if a linked list is circular, use two pointers, one moving at twice the speed of the other. If they meet, the list is circular.

• Use two pointers, one moving at twice the speed of the other

• If the faster pointer catches up to the slower pointer, the list is circular

• If the faster pointer reaches the end of the list, the list is not circular

Find the merge point of 2 linked lists.

• Traverse both lists and find their lengths

• Move the pointer of the longer list to the same distance as the shorter list

• Move both pointers until they meet at the merge point

• If there is no merge point, return null

To find a string in a sorted array of strings.

• Use binary search algorithm to search for the string in the array.

• Compare the search string with the middle element of the array.

• If the search string is less than the middle element, search in the left half of the array.

• If the search string is greater than the middle element, search in the right half of the array.

• Repeat the process until the string is found or the search sp

Singleton class is a design pattern that restricts the instantiation of a class to one object.

• To create a singleton, we need to make the constructor private and provide a static method to get the instance of the class.

• To delete the singleton object, we can simply set the instance to null.

• Singletons are useful when we need to ensure that only one instance of a class exists throughout the application.

• Example: Logger clas...read more

Dynamic memory allocation in C/C++ is done using malloc(), calloc(), realloc() functions. C++ also has new and delete operators.

• malloc() allocates memory block of specified size

• calloc() allocates memory block and initializes it to zero

• realloc() changes the size of previously allocated memory block

• new operator in C++ allocates memory and calls constructor

• delete operator in C++ deallocates memory and calls destructor