HM Constructions Interview Questions and Answers

To find missing number, duplicate, largest and smallest elements, and multiple duplicates in an array.

• To find missing number, calculate the sum of all numbers from 1 to 100 and subtract the sum of the given array.

• To find duplicate, use a hash set to store elements as you iterate through the array and check for duplicates.

• To find largest and smallest elements, initialize variables with the first element and update them while iterating through the array.

• To find multiple duplica...read more

Answers to common programming interview questions.

• Constructor is a special method that is called when an object is created.

• OOPs is Object-Oriented Programming which focuses on objects and their interactions.

• Abstraction is a concept of hiding implementation details while interface is a blueprint of a class.

• Checked exceptions are checked at compile-time while unchecked exceptions are not.

• Throw keyword is used to throw an exception while throws keyword is used to declare an exce...read more

Java Virtual Machine (JVM) is responsible for executing Java programs.

• JVM is a virtual machine that interprets compiled Java code.

• It provides a runtime environment for Java programs to run.

• JVM is platform-independent and provides memory management, security, and other features.

• Java programs are compiled into bytecode, which is then executed by the JVM.

• JVM is responsible for loading classes, verifying bytecode, and executing the program.

Servlets are still relevant for web development in Java

• Servlets provide a lightweight and efficient way to handle HTTP requests and responses

• They can be used for dynamic web content generation and server-side processing

• Servlets are extensible and can be integrated with other Java technologies like JSP and JDBC

• Alternative technologies like Spring MVC and RESTful APIs build on top of Servlets

• Removing Servlets would break backward compatibility and disrupt existing Java web appl...read more

To reverse an array of strings, iterate through the array and swap elements from start to end.

• Iterate through the array using two pointers, one starting from the beginning and the other from the end.

• Swap the elements at the two pointers and move the pointers towards the center until they meet or cross each other.

To find the median in 2 arrays of strings, merge the arrays, sort them, and then calculate the median.

• Merge the two arrays into one array

• Sort the merged array

• Calculate the median based on the length of the array (odd or even number of elements)

Array is a fixed-size collection of elements of the same data type, while ArrayList is a dynamic collection that can grow or shrink in size.

• Array is a static data structure with a fixed size, while ArrayList is a dynamic data structure that can resize itself.

• Arrays can hold primitive data types and objects, while ArrayList can only hold objects.

• Arrays are faster than ArrayList for accessing elements, but ArrayList is more flexible and easier to work with.

• Example: String[] nam...read more