Spectrum Metro Interview Questions and Answers

Interface defines a contract while Abstraction hides implementation details.

• Interface is a blueprint of a class that defines the methods and properties that the class should implement.

• Abstraction is a way of hiding the implementation details of a class and exposing only the necessary details to the user.

• Interface is used to achieve multiple inheritance in Java.

• Abstraction can be achieved through abstract classes and interfaces.

• Interface is used to achieve loose coupling betwe...read more

To prevent application downtime, implement redundancy, monitoring, automation, and disaster recovery plans.

• Implement redundancy by using load balancers, multiple servers, and failover systems.

• Set up monitoring tools to detect issues proactively and alert the team.

• Automate processes like deployments, scaling, and backups to reduce human errors.

• Create disaster recovery plans with backups, replication, and failover strategies.

• Regularly test the disaster recovery plans to ensure ...read more

Collection hierarchy in Java refers to the relationship between different types of collections such as List, Set, and Map.

• Java collections framework includes interfaces like Collection, List, Set, and Map.

• List interface extends Collection interface and represents an ordered collection of elements.

• Set interface extends Collection interface and represents a collection of unique elements.

• Map interface represents a mapping between keys and values.

Iterate through a map and write code to perform operations on each key-value pair.

• Use a for loop to iterate through the map

• Access the key and value of each pair using the iterator

• Perform desired operations on the key-value pairs

Hash table is a data structure that stores key-value pairs and uses a hash function to map keys to their corresponding values.

• Hash table consists of an array of buckets, each containing a linked list of key-value pairs.

• When inserting a key-value pair, the hash function is used to determine the index of the bucket where the pair should be stored.

• During retrieval, the hash function is used again to find the correct bucket and then search the linked list for the key.

• Hash collisi...read more

Default method is a method in an interface with a default implementation.

• Introduced in Java 8 to allow adding new methods to interfaces without breaking existing implementations

• Default methods can be overridden in implementing classes

• Used to provide a default implementation for methods in interfaces