CitiusTech Java Developer Interview Questions and Answers

Count the frequency of each word in a given string.

• Split the string by spaces to get individual words.

• Use a hashmap to store each word and its frequency.

• Iterate through the words and update the hashmap accordingly.

• Print out the words and their frequencies in any order.

Comparable is an interface used for natural ordering, while Comparator is an interface used for custom ordering in Java.

• Comparable interface is used to define the natural ordering of objects. It is implemented by the class whose objects are to be compared.

• Comparator interface is used to define custom ordering of objects. It is implemented by a separate class.

• Comparable interface has a single method, compareTo(), which compares the current object with another object.

• Comparator...read more

Azure and AWS are two major cloud service providers offering similar services but with some differences in features and pricing.

• AWS is the oldest and most widely used cloud service provider, while Azure is catching up quickly.

• Azure is known for its strong integration with Microsoft products and services, while AWS has a wider range of third-party integrations.

• AWS has a larger global presence with more data centers worldwide compared to Azure.

• Pricing models differ between the ...read more

Multithreading in Java allows for concurrent execution of multiple tasks, improving performance and responsiveness.

• 1. Improved performance by utilizing multiple CPU cores efficiently.

• 2. Enhanced responsiveness as tasks can run concurrently without blocking each other.

• 3. Simplified coding for complex tasks by breaking them into smaller threads.

• 4. Facilitates better resource utilization and scalability.

• 5. Examples: parallel processing in data analysis, handling multiple client ...read more

Context API in React is a way to pass data through the component tree without having to pass props down manually at every level.

• Context API provides a way to share values like themes, user data, etc. across the component tree without having to pass props down manually.

• It consists of three main parts: Provider, Consumer, and useContext hook.

• Provider component allows the data to be passed down to the tree, Consumer component consumes the data, and useContext hook allows functio...read more

Redux is a predictable state container for JavaScript apps, commonly used with React for managing application state.

• Redux helps manage the state of an application in a predictable way

• It provides a single source of truth for the state of the application

• Actions are dispatched to update the state in a predictable manner

• Reducers specify how the state changes in response to actions

• Redux is commonly used with React to manage the state of components

Count duplicates in an int array

• Create a HashMap to store the count of each element in the array

• Iterate through the array and update the count in the HashMap

• Count the elements with count greater than 1 as duplicates