Crif Solutions Interview Questions and Answers

Polymorphism allows objects of different classes to be treated as objects of a common superclass. Interface is a contract that defines a set of methods that a class must implement.

• Polymorphism allows for flexibility in programming by enabling a single interface to be used to represent multiple types of objects

• Interfaces in Java are similar to abstract classes, but they cannot contain any implementation code

• Abstract classes can have both abstract and concrete methods, while in...read more

Static keyword is used to create class-level variables and methods, while final keyword is used to make a variable constant.

• Static keyword is used to create variables and methods that belong to the class itself, rather than to any specific instance of the class.

• Final keyword is used to make a variable constant and cannot be changed once it has been assigned a value.

• Static variables are shared among all instances of a class, while final variables are unique to each instance.

JVM is the Java Virtual Machine that executes Java bytecode. JRE is the Java Runtime Environment that includes JVM and libraries. JDK is the Java Development Kit that includes JRE and development tools.

• JVM is the virtual machine that runs Java bytecode and provides a runtime environment for Java programs.

• JRE includes JVM along with libraries and other components necessary to run Java applications.

• JDK is a development kit that includes JRE and development tools such as compile...read more

HashMap internally uses an array of linked lists to store key-value pairs, with keys hashed to determine the index.

• HashMap uses hashing to determine the index of key-value pairs in the array.

• Each index in the array can store multiple key-value pairs in a linked list.

• When a key is inserted, its hash code is used to find the appropriate index in the array.

• If multiple keys hash to the same index, they are stored in a linked list at that index.

• HashMap dynamically resizes the arra...read more

Spring Boot is a framework for building Java-based web applications with minimal configuration.

• Spring Boot simplifies the process of creating standalone, production-grade Spring-based applications.

• It provides a range of features like embedded servers, auto-configuration, and production-ready metrics.

• Spring Boot allows developers to quickly set up and run RESTful web services using annotations and minimal XML configuration.