MocDoc Application Support Engineer 1 Interview Questions and Answers

Classes can have both implementation and data members, while interfaces can only have method signatures.

• Classes can have constructors, interfaces cannot.

• Classes can have access modifiers for their members, interfaces cannot.

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

• Interfaces are used to achieve abstraction and multiple inheritance in Java.

• Example: Class 'Animal' can have methods li...read more

Multithreading allows multiple threads to exist within the context of a single process, while multiprocessing involves multiple processes running concurrently.

• Multithreading allows multiple threads to share the same memory space and resources of a single process, while multiprocessing involves separate memory space for each process.

• Multithreading is more lightweight and efficient compared to multiprocessing as threads ...read more

React DOM is a package that provides methods for updating the DOM in response to React components.

• React DOM is used to render React components to the DOM.

• It provides methods like ReactDOM.render() to render components.

• React DOM efficiently updates the DOM when the state of a component changes.

• It handles events and updates the DOM accordingly.

• React DOM is separate from React itself, allowing for flexibility in rendering

MVC in Rails is a software design pattern that separates the application into three main components: Model, View, and Controller.

• Model: Represents the data and business logic of the application.

• View: Represents the user interface of the application.

• Controller: Acts as an intermediary between the Model and View, handling user input and updating the Model accordingly.

• Example: In a Rails application, a User model would ha...read more

Find the 2nd largest element in an array of strings.

• Sort the array in descending order

• Access the element at index 1 to get the 2nd largest element

To get the top view of a binary tree, we need to find the nodes that are visible when looking at the tree from the top.

• Start from the root node and assign it a horizontal distance of 0.

• Traverse the tree using a queue and keep track of the horizontal distance of each node.

• For each horizontal distance, only keep the node with the smallest level in the result.

• Repeat the process for left and right child nodes, updating the

NotificationCenter is a system that enables communication between different parts of an application.

• NotificationCenter allows components of an application to communicate without having direct references to each other.

• It uses the observer pattern where objects register themselves as observers for specific notifications.

• Notifications can be posted to the NotificationCenter with optional data.

• Observers can then receive an...read more

Design a Twitter feed using SOLID principles

• Separate classes for each responsibility (Single Responsibility Principle)

• Use interfaces to define behavior and allow for easy swapping of implementations (Open/Closed Principle)

• Dependency Injection to decouple components and make testing easier (Dependency Inversion Principle)

• Liskov Substitution Principle to ensure derived classes can be substituted for their base classes wi...read more

Find the first occurrence of a given number in a sorted array.

• Use binary search to efficiently find the first occurrence of the number.

• Keep track of the index of the first occurrence as you search through the array.

• Return the index of the first occurrence once found.

Garbage collector algorithm manages memory allocation and deallocation in a program.

• Garbage collector automatically frees up memory that is no longer in use.

• It identifies and removes objects that are no longer referenced by the program.

• There are different types of garbage collector algorithms such as mark-and-sweep, reference counting, and generational.

• Java and .NET languages use garbage collector by default.

• Garbage co...read more