10+ MACFAST Interview Questions and Answers

Use the tilt method to pour exact half water from one container to other without measurements.

• Fill both containers with water

• Tilt one container slowly until water reaches the halfway mark

• Stop pouring when the water level reaches halfway in the other container

The dog will take 28 days to reach the ground.

• The dog climbs 1 foot (3 feet climb - 2 feet drop) each day.

• It needs to climb 30 feet to reach the ground.

• So, it will take 30 days to climb 30 feet, but it will already be on the ground on the 28th day.

Swap adjacent elements, reverse and insert in a linked list.

• To swap adjacent elements, we need to traverse the linked list and swap the nodes.

• To reverse a linked list, we need to traverse the list and change the pointers of each node to point to the previous node.

• To insert a node in a linked list, we need to find the position where we want to insert the node and change the pointers of the nodes accordingly.

Different types of joins in SQL include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN: Returns rows when there is at least one match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

Shared pointers are a type of smart pointer used in C++ to manage memory allocation.

• Shared pointers allow multiple pointers to refer to the same object, automatically managing the object's lifetime.

• They use reference counting to keep track of how many pointers are pointing to the object.

• When the last shared pointer goes out of scope, the object is automatically deleted.

• They help prevent memory leaks and dangling pointers.

• Example: std::shared_ptr ptr1 = std::make_shared();

• Exam...read more

Overloading is using the same method name with different parameters. Overriding is creating a new implementation of a method in a subclass.

• Overloading allows multiple methods with the same name but different parameters.

• Overriding allows a subclass to provide its own implementation of a method from its superclass.

• Overloading is resolved at compile-time while overriding is resolved at runtime.

• Examples of overloading: print(int), print(float), print(string)

• Examples of overriding...read more

The 4 pillars of Java are abstraction, encapsulation, inheritance, and polymorphism.

• Abstraction: Hides complex implementation details and only shows the necessary features.

• Encapsulation: Bundles data and methods into a single unit, preventing direct access to data.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Enables objects to be treated as instances of their parent class.

Count occurrences of a string in another string and find second highest salary in SQL.

• Use a loop to iterate through the second string and check for occurrences of the first string.

• Use a counter variable to keep track of the number of occurrences found.

• In SQL, use a subquery to find the employee with the second highest salary by ordering the salaries in descending order and selecting the second row.

System level setup in JVM/JRE and performance engineering

• System level setup involves configuring JVM/JRE parameters such as heap size, garbage collection, and thread pool size

• Performance engineering involves analyzing and optimizing system performance through load testing, profiling, and tuning

• Tools such as JMeter, JProfiler, and VisualVM can be used for performance engineering

• Performance engineering also involves identifying and addressing bottlenecks in the system architect...read more

The new keyword is used in C# to create an instance of a class or structure.

• Used to instantiate objects in C#

• Can be used with constructors to initialize object properties

• Helps in creating instances of classes or structures

Dependency injection in Angular is a design pattern where components are given their dependencies rather than creating them.

• Allows for easier testing and maintenance of code

• Promotes reusability and modularity

• Reduces tight coupling between components

• Example: Injecting a service into a component constructor

Interface defines only method signatures while abstract class can have method implementations.

• Interface cannot have method implementations, only method signatures.

• Abstract class can have method implementations and variables.

• A class can implement multiple interfaces but can inherit only one abstract class.

• Interfaces are used for defining contracts while abstract classes are used for code reusability.

Pipes in Angular are used for transforming data in templates.

• Pipes are used to format data before displaying it in the view

• They can be used for currency, date, uppercase/lowercase transformations, etc.

• Example: {{ birthday | date:'MM/dd/yyyy' }}

The 'using' keyword is used in C# to ensure that an object is disposed of properly after use.

• Automatically disposes of resources when they are no longer needed

• Simplifies code by handling cleanup tasks

• Example: using (var file = new FileStream("example.txt", FileMode.Open)) { // code here }

Oops concept is a programming paradigm based on objects and classes. Dependency injection is a design pattern used to remove hard-coded dependencies.

• Oops concept focuses on objects, classes, inheritance, polymorphism, and encapsulation

• Dependency injection is a design pattern where the dependencies of a class are injected from the outside rather than created within the class

• Example of dependency injection is using constructor injection or setter injection in Spring framework

Program to reverse a linked list

• Create a function to reverse the linked list by changing the next pointers

• Use three pointers to keep track of current, previous, and next nodes

• Iterate through the list and update the pointers accordingly

• Return the new head of the reversed linked list

Java 8 introduced new features for working with strings.

• Java 8 added the join() method to String class for joining strings with a delimiter.

• The String class now has methods like chars(), codePoints(), and lines() for working with characters and lines.

• The StringJoiner class can be used to construct sequences of characters separated by a delimiter.