10+ UKG Senior Software Engineer Interview Questions and Answers

Java is a high-level programming language developed by Sun Microsystems (now owned by Oracle) in 1995.

• Java is platform-independent, meaning it can run on any device with a Java Virtual Machine (JVM).

• It is object-oriented and designed to have as few implementation dependencies as possible.

• Java is widely used for building web applications, mobile apps, and enterprise software.

• James Gosling, Mike Sheridan, and Patrick Naughton are credited with the development of Java.

ApplicationContext is an interface for providing configuration information to an application.

• ApplicationContext is the central interface in a Spring application for providing configuration information to the application.

• It is responsible for instantiating, configuring, and assembling beans.

• ApplicationContext can load bean definitions, wire beans together, and dispense beans upon request.

• It provides a means for resolving text messages, accessing resources, and loading file res...read more

Iterate through array to find 2nd largest number

• Iterate through array and keep track of largest and second largest numbers

• Handle edge cases like duplicates and empty array

• Example: ['3', '5', '2', '7', '5'] should return 5 as the 2nd largest number

Program to find duplicate strings in an array

• Iterate through the array and store each string in a HashSet

• If a string is already in the HashSet, it is a duplicate

• Return a list of all duplicate strings found

Java 8 introduced several new features including lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to write code in a more concise way by replacing anonymous classes.

• Functional interfaces are interfaces with a single abstract method, which can be implemented using lambda expressions.

• Streams provide a way to work with sequences of elements and perform operations like filter, map, reduce, etc.

• Default methods allow interfaces to...read more

Yes, Java is platform independent due to its ability to compile code into bytecode that can run on any platform with a Java Virtual Machine (JVM).

• Java code is compiled into bytecode which can run on any platform with a JVM

• JVM acts as an abstraction layer between the Java code and the underlying platform

• Java's 'write once, run anywhere' principle allows for platform independence

Reverse a linked list by changing the direction of pointers.

• Start with three pointers: current, previous, and next.

• Iterate through the linked list, updating pointers to reverse the direction.

• Return the new head of the reversed linked list.

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• Retrieving a value involves hashing the key to find the index and then traversing the linked list ...read more

AOT compiles code before runtime, JIT compiles code during runtime.

• AOT stands for Ahead Of Time compilation, compiles code before execution

• JIT stands for Just In Time compilation, compiles code during execution

• AOT produces machine code that can be executed directly

• JIT converts code into machine code as needed, optimizing performance

• Examples: AOT - Angular, JIT - Java Virtual Machine

Swapping two numbers without using a temporary variable.

• Use XOR operation to swap two numbers without using a temporary variable.

• Example: a = 5, b = 10. After swapping, a = 10, b = 5.

psvm in Java stands for public static void main, which is the entry point for a Java program.

• psvm is the method signature for the main method in Java programs.

• It is used to start the execution of a Java program.

• It must be declared as public, static, and void.

• It takes an array of strings as an argument, which can be used to pass command line arguments.